Siddharth B ( 2av16cv446 ).pdf

VISVESVARAYA TECHNOLOGICAL UNIVERSITY Belgaum, Karnataka-590018

An Internship report Submitted by:

SIDDHARTH BALLODI

[2AV16CV446]

Submitted in partial fulfillment of the requirement for the award of degree

BACHELOR OF ENGINEERING IN CIVIL ENGINEERING Under the Guidance of Mr. K.B.V.PATHI, B.E. EE (RTD)

- PRINCIPAL ENGINEER

Mr. A.S.SOMASHEKARA, B.E. EE (RTD) - CHIEF TECHNICAL OFFICER Mr. SREENIVASA C

- TECHNICAL MANAGER

M/S KARNATAKA TEST HOUSE PVT. LTD. NABL Accredited Laboratory as per ISO/IEC 17025

CERTIFICATE M/s KARNATAKA TEST HOUSE Pvt Ltd. NABL ACCREDITED MATERIAL TESTING LABORATORY ISO/IEC 17025 No.778/44, 8th cross, Triveni Road, Gokul 1st stage, 2nd phase, Bangalore 560054

This is to certify that the INTERNSHIP at KARNATAKA TEST HOUSE PVT LTD has been successfully completed by

SIDDHARTH BALLODI [2AV16CV446]

Students of the VIII semester B.E (CIVILENGINEERING) from The A.G.M.R. COLLEGE OF ENGINEERING AND TECHNOLOGY under VISVESVARAYA TECHNOLOGICAL UNIVERSITY BELAGAVI during the academic year 2018-19. The internship report satisfies the requirements with respect to the work prescribed in the company.

SREENIVASA C Technical manager KARNATAKA TEST HOUSE PVT LTD

INTERNSHIP REPORT

2018-2019

ACKNOWLEDGEMENT The satisfaction that accompanies the successful completion of any task would be incomplete without mention of the people who made it possible, whose constant guidance and encouragement, crowned our efforts with success. We take this opportunity to express our deepest gratitude and appreciation to all those who helped us directly or indirectly towards the successful completion of this internship. Firstly, we would like to express my deep sense of gratitude to our beloved Principal Dr. SUNILKUMAR.D. For his continuous effort in creating a competitive environment in our college and encouraging throughout this course in AGMR COLLEGE OF ENGINEERING AND TECHNOLOGY VARUR. We would like to convey my heartfelt thanks to VIKAS BIRADAR, Head of Department of Civil Engineering for giving me the opportunity to embark upon this internship and for his continued encouragement throughout the preparation of this internship report. We would like to convey my heartfelt thanks to SREENIVASA .C Technical Manager of Karnataka Test House Pvt. Ltd. Bangalore for giving me an opportunity to pursue internship in his company. We would like to thank sincerely to my Internship Co-Ordinator Mr. Amit Kumar Salgar & Internship guide Mr. Akash R for their invaluable guidance, constant assistance, support, endurance and constructive suggestions for the betterment of this internship report. We also wish to thank all the Staff members of organization for helping me directly or indirectly in completing this work successfully.

Place: Bangalore BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 3

INTERNSHIP REPORT

2018-2019 ABSTRACT

The internship report is based on Geotechnical Engineering and Concrete Technology aspects and some index properties of soil and Mix Design for Concrete. Geotechnical Engineering is one of the youngest disciplines of Civil Engineering involving the study of soil, its behavior and application as an Engineering material. Good soil Engineering embodies the use of the best practices in exploration, testing, design and construction control, in the addition to the basic idealized theories. Concrete Mix Design is process of proportioning the cement, aggregates, water, admixture to make the structure for more serviceability, economical and resist extreme environmental conditions. The internship report gives the details about the company background including Mission, Vision and Moto. It also explains the overall familiarity in my internship tenure. It also records the overall work we have been executing. It gives a high light of what we had been doing and the main works of Geotechnical Engineering and Concrete Technology. It is obvious that the internship has a positive effect in improving the skills and different abilities. The report will confirm the benefits of internship program, which has not only been an exceptional learning experience, but has also given has a significant base on which we could build my professional Engineering care

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 4

INTERNSHIP REPORT

2018-2019 INDEX

SL. NO.

CONTENTS GEOTECHNICAL ENGINEERING

1.

PAGE.NO.

01 - 13

a) INTRODUCTION b) SOIL EXPLORATION LABORATORY TESTS CONDUCTED ON SOIL a) MOISTURE CONTENT b) SIEVE ANALYSIS OF SOIL c) WATER ABSORPTION AND SPECIFIC GRVITY TEST d) ATTERBERG’S LIMITS i.

2.

LIQUID LIMIT (CASAGRANDE’S AND CONE

14 – 60

PENETRATION TEST) ii.

PLASTIC LIMIT

e) COMPACTION TEST f) DIRECT SHEAR TEST g) FREE SWELL INDEX OF SOIL h) CBR (CALIFORNIA BEARING RATIO)

3.

CONCRETE TECHNOLOGY AND MATERIAL TESTING

61 – 144

CONCRETE: INTRODUCTION TO CONCRETE LAB TESTS ON CONCRETE a) COMPRESSIVE STRENGTH OF CONCRETE 3.A.

CEMENT: INTRODUCTION TO CEMENT

61 – 77

LAB TESTS ON CEMENT a) NORMAL CONSISTENCY OF CEMENT b) INITIAL AND FINAL SETTING TIME OF CEMENT c) COMPRESSIVE STRENGTH OF CEMENT AGGREGATES: INTRODUCTION TO AGGREGATES

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 5

INTERNSHIP REPORT

2018-2019

A.COARSE AGGREGATE TESTS: a) SIEVE ANALYSIS b) SHAPE TESTS ( FLAKINES AND ELONGATION INDEX) 3.B.

78 - 107

c) BULK DENSITY (LOOSE AND COMPACT) d) WATER ABSORPTION AND SPECIFI GRAVITY e) AGGREGATE IMPACT VALUE f) AGGREGATE CRUSHING VALUE g) LOS ANGELES ABRASION RESISTANCE h) 10% FINER VALUE B.FINE AGGREGATE TESTS: a) SIEVE ANALYSIS

3.C

b) SPECIFIC GRAVITY AND WATER ABSORPTION

108-123

c) BULK DENSITY (LOOSE AND COMPACTED) d) SILT CONTENT C.BLOCKS HOLLOW/SOLID: 3.D

a) WATER ABSORPTION

124-134

b) COMPRESSIVE STRENGTH c) BLOCK DENSITY

3.E

BRICKS a) WATER ABSORPTION

135-144

b) COMPRESSIVE STRENGTH

4

5

6

REINFORCEMENT STEEL TILES

REFERENCE

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

145-160

161-167

168-171

Page 6

INTERNSHIP REPORT

2018-2019

1.0 GEOTECHNICAL ENGINEERING

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 7

INTERNSHIP REPORT

2018-2019 INTRODUCTION.

GEOTECHNICAL INVESTIGATION: The field and laboratory studies carried out for obtaining the necessary information about the subsoil characteristics including the position of ground water are termed as “Geotechnical Investigation” The very main purpose of geotechnical investigation is to conduct soil investigation and its features for the site where building constructions take place. Site investigation refers to the methodology of determining surface and subsurface features of the proposed area.

APPLICATIONS OF GEO TECHNICAL ENGINEERING  Rock mechanics behavior tests viscous Elasto plasticity nonlinearity lining support system for tunnel surrounding rocks rheological damage and fracture rheology in soft soils.  Engineering geology to solve Engineering problems such as design of foundations, slopes, excavations, dams, tunnels.  Other Civil, Mining and Environmental Engineering projects relating to the mechanical response of the ground and the water within it.  Research work being undertaken in the Geo Engineering Centre includes studies on geosynthetics, long term performance of landfill liners, shallow and deep foundations, tunnels and deep excavations, pipes, culverts and other buried infrastructure as well as Geotechnical Earthquake Engineering.  To find the shear strength of soil, physical and mechanical properties for

eg.

Construction.

DEFINITION OF SOIL Soil is an un-aggregated or un-cemented material of an earth crust which are normally formed due to disintegration of the original parent rock. The term ‘soil’ in Geotechnical Engineering is defined as an unconsolidated material, composed of solid particles, produced by the disintegration of rocks.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 8

INTERNSHIP REPORT

2018-2019

OBJECTIVES OF SOIL EXPLORATION PROGRAM The information from soil investigations will enable a Civil engineer to plan, decide, design, and execute a construction project. Soil investigations are done to obtain the information that is useful for one or more of the following purposes.  To know the geological condition of rock and soil formation.  To establish the groundwater levels and determine the properties of water.  To select the type and depth of foundation for proposed structure  To determine the bearing capacity of the site.  To estimate the probable maximum and differential settlements.  To predict the lateral earth pressure against retaining walls and abutments.  To select suitable construction techniques  To predict and to solve potential foundation problems  To ascertain the suitability of the soil as a construction material.  To determine soil properties required for design  Establish procedures for soil improvement to suit design purpose  To investigate the safety of existing structures and to suggest the remedial measures.  To observe the soil the soil performance after construction.  To locate suitable transportation routes.

SOIL INVESTIGATIONS INVOLVE THE FOLLOWING STEPS:  Planning the details and sequence of operations  Collection of soil samples from the field  Conducting all field tests for determining the strength and compressibility characteristics of the soil  Study of ground water level conditions and collection of water samples for chemical analysis  Geophysical exploration if necessary  Testing in the laboratory of all samples of soil, rock, and water  Preparation of drawings and charts  Analysis of the results of the tests  Preparation of reports

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 9

INTERNSHIP REPORT

2018-2019

SOIL EXPLORATION METHODS A. Trial pit B. Boring

A. TRIAL PIT  Applicable to all types of soils  Provide for visual examination in their natural condition  Disturbed and undisturbed soil samples can be obtained at excavated depths  Depth of investigation: Foundation depth.

ADVANTAGES  Cost effective  Provide detailed information of stratigraphy  Sufficient quantities of disturbed soils are available for testing  Undisturbed samples can be carved out from the pits  Field tests can be conducted at the bottom of the pits

DISADVANTAGES  Depth limited for open foundation  Deep pits uneconomical  Excavation below groundwater level is difficult  Too many pits may scar site and require backfill soils.  Undisturbed sampling is not recovered in loose soils  UDS will be Collapse in granular soils or below ground water table

B. EXPLORATORY (ROTARY) BORINGS Boring is carried out in the relatively soft and unfermented ground (engineering ‘soil’) which is normally found close to ground surface. The techniques used vary widely across the world. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 10

INTERNSHIP REPORT

2018-2019

Location, spacing and depth of borings It depends on:  Type of structure  Size of the structure  Weight coming from the structure General guidelines for location and depth of bore holes Boreholes are generally located at  The building corners  The Centre of the site  Where heavily loaded columns or machinery pads are proposed.  At least one boring should be taken to a deeper stratum, probably up to the bedrock if practicable  Other borings may be taken at least to significant stress level.

METHODS OF BORING FOR SOIL INVESTIGATIONS:

Figure 1: Soil Sampling by Hand Augur

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 11

INTERNSHIP REPORT

2018-2019 HAND AUGUR BORING: The examination of the soil for ordinary buildings can be done by a post hole auger. The auger is held vertically and is driven into the ground by rotating its handle. At every 30 cm of depth, the auger is taken out and the soil samples collected.

WASH (ROTARY) BORING Wash boring is commonly used for boring in heavy structures like multi story buildings, Bridges, Canals, Aqueducts etc. The hole is advanced by an rotary drilling and then a casing pipe is pushed to prevent the sides from caving in. A stream of water under pressure is forced through the rod into the hole. The loosened soil in Figure 2:- Wash boring

suspension in water is collected in a tub.

PERCUSSION BORING In this method, the substratum is broken by repeated blows by a bit or chisels. Water is circulated in the hole and then the slurry is bailed out of the hole. (i) Disturbed sample: Disturbed sample is a sample in which soil structure is significantly or completely disturbed and the moisture content may also differ from in-situ value. The particle size distribution of in-situ soil is preserved. These samples are required for identification and classification tests. (ii) Undisturbed sample: Undisturbed sample is a sample which retains as closely as practicable, the true in-situ structure and moisture content of soil. These samples are required for

Figure 4:- Rotary boring

shear strength, permeability and consolidation tests. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 12

INTERNSHIP REPORT

2018-2019

CORE DRILLING When rocks are to be penetrated for examination, core drilling is resorted to. In this process, a hole is made by rotating a hollow steel tube having a cutting bit at its end.

SOIL SAMPLES:

FIELD AND LABORATORY TESTING

Figure 3: Collected soil samples and Soaking in water for lab tests

Figure 4: Oven drying and Oven dried soil sample

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 13

INTERNSHIP REPORT

2018-2019

Field Tests: The commonly adopted field tests are: 1) Standard penetration test, 2) Plate load test, 3) Vane shear test and 4) Pressure meter test etc.

Laboratory Tests: A set of laboratory tests are required to be done to obtain the soil parameters for the design of foundation. These tests are: 1) moisture content test, 2) specific gravity of soil tests, 3) sieve analysis, 4) atterberg’s limits (plastic and liquid limits), 5) unconfined compression test, 6) direct shear test, 7) triaxial test, 8) California bearing ratio, 9) consolidation, 10) free soil index test, 11) hydrometer test, 12) Compressibility, 13) Permeability, 14) Chemical and Mineralogical Composition, and 15) Soil Classification etc.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 14

INTERNSHIP REPORT

2018-2019

2.0. LABORATORY TESTING OF SOIL 1) MOISTURE CONTENT OF SOIL BY OVEN DRYING METHOD. DEFINITION: The quantity of water content present in soil is known as moisture content or water content of soil. SIGNIFICANCE:  The knowledge of the natural moisture content is essential in all studies and determining the bearing capacity and settlement of soil.  It gives a idea about the state of soil in field

Figure 5: Containers and Soil Sample REFERENCE STANDARD: IS2720 PART 2 (1973) AIM: For determination of the moisture content of soil by oven drying method. APPARATUS USED:  Oven (1050C to 1100C min.)  Metal container  Balance (0.01 g accuracy) PROCEDURE:  The number of the container is recorded. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 15

INTERNSHIP REPORT

2018-2019

 The container is cleaned, dried and weighed as W1 gm  About 15-30 g of soil is placed in the container and the weight of soil with the sample is recorded as W2 gm.  The can with the soil is placed in oven for 24hours maintained at a temperature 1050 to 1100C.  After drying the container is removed from the oven and allowed to cool at room temperature.  After cooling the soil with container is weighed.(W3)  The water content of the soil specimen is found out by using formulas. CALCULATION:

W1=Mass of container in gm W2=Mass of container and wet soil in gm W3=Mass of container and dry soil in gm TABULAR COLUMN:

PARAMETER

TRAIL-1

TRAIL-2

TRAIL-3

TRAIL-4

Wt. of empty cup(W1 g)

10.2

10.3

11.2

9.5

Wt. of wet soil+ cup(W2 g)

19.3

15.7

19.8

17.2

Wt. of dry soil+ cup(W3 g)

17.4

16.8

18.7

15.6

Wt. of water (WW= W2-W3)g

1.9

2.8

1.1

1.6

Wt. of dry soil (Ws= W3-W1)g

7.2

6.5

7.5

6.1

26.38

43.07

14.66

26.23

Water content in percentage (W=WW/Ws)% Avg. water content %

27.58

RESULTS: The average natural water content of the soil specimen is 27.58 % BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 16

INTERNSHIP REPORT

2018-2019

2) SIEVE ANALYSYS OF SOIL DEFINITION: It is a procedure used to assess the particle size distribution of a soil by allowing the soil material to pass through a series of sieves of progressively smaller mesh size and weighing the amount of material that is retained on each sieve as a fraction of the whole mass. SIGNIFICANCE:  The distribution of different grain sizes affects the engineering properties of the soil.  Grain size analysis provides the grain size distribution, and it is required in classifying the soil

Figure 6: Sieve and Soil sample

REFERENCE STANDARD: IS 2720 (Part 4) – 1985 AIM: For determination of particle size distribution of fine, coarse and all-in-aggregates by sieving. APPARATUS USED: 

Balance  Sieves sizes ranges from 10mm, 4.75mm, 2.36, 2mm, 1.18mm, 600mic, 425mic, 300mic, 150mic, 75mic and then pan  Sieve shaker

Figure 7:- Sieve sets

PROCEDURE:  Soil sample is oven dried at about 105°C to 110°C is taken  Weight of soil sample taken for the test = 200g  The sieve sets are kept on the sieve shaker for about Duration of Minimum 10 minutes.  Weight of soil sample retained in each sieve is recorded and Percentage finer is calculated  Semi log Graph is plotted between particle size and percentage finer  Uniformity Coefficient Cu =D60 / D10  Coefficient of curvature Cc =D30²/ (D60xD10)  The results of mechanical analysis (sieve and hydrometer analyses) are generally presented by semi-logarithmic plots known as particle-size distribution curves. The particle diameters are plotted in log scale.

TABULAR COLUMN: BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 17

INTERNSHIP REPORT

2018-2019

Table: 1 GRAIN SIZE ANALYSIS ( MECHANICAL ) Project: Guddahalli Depth: 2 – 2.5 m Project: Guddahalli Depth: 2 – 2.5 m Date of testing: 18/7/18 Weight of sample Date of testing: 18/7/18 Weight of sample Borehole No.: 01 taken: 150g Borehole No.: 02 taken: 150g Sieve Wt. Cum. Cum. % Sieve Wt. Cum. Cum% dia. retained wt. retained % passing dia. mm retained wt. retained % Mm g retained in % (100-C) g retained in % passing in gm (C) in gm (C) (100-C) 10.0 0 0 0 100 10.0 0 0 0 100 4.75 0 0 0 100 4.75 1.5 1.5 1 99 2.36 0 0 0 100 2.36 13.4 14.9 9.93 90.07 2.0 0 0 0 100 2.0 2.7 17.6 11.73 88.27 1.18 12.3 12.3 8.2 91.8 1.18 25.9 43.5 29 71 0.60 25.9 38.2 25.46 74.54 0.60 20.3 63.8 42.53 57.47 0.425 29.7 67.9 45.26 54.74 0.425 13.5 77.3 51.53 48.47 0.30 16.1 84 56 44 0.30 7.0 84.3 56.2 43.8 0.15 41.7 125.7 83.8 16.2 0.15 25.6 109.9 73.26 26.24 0.075 21.8 147.5 98.33 1.67 0.075 27.4 137.3 91.53 8.47 Pan 2.3 150 100 0 Pan 11.43 150 100 0 Total 149.8 ≈ Σ= Total 148.73 ≈ Σ= 150 417.05 150 453.84 Mass loss during sieve analysis = 0.133% Mass loss during sieve analysis = 0.84% Fineness modulus= 4.17 Fineness modulus= 4.53 Table: 2 GRAIN SIZE ANALYSIS ( MECHANICAL ) Project: Guddahalli Depth: 2 – 2.5 m Project: Guddahalli Depth: 2 – 2.5 m Date of testing: 18/7/18 Weight of sample Date of testing: 18/7/18 Weight of sample Borehole No.: 03 taken: 150g Borehole No.: 04 taken: 100g Sieve Wt. Cum. Cum. % Sieve Wt. Cum. Cum% dia. retained wt. retained % passing dia. mm retained wt. retained % mm g retained in % (100-C) g retained in % passing in gm (C) in gm (C) (100-C) 10.0 0 0 0 100 10.0 0 0 0 100 4.75 1.9 1.9 1.27 98.73 4.75 4.8 4.8 4.8 95.2 2.36 5.4 7.3 4.87 95.13 2.36 10.8 15.6 15.6 84.4 2.0 10.8 18.1 12.07 87.93 2.0 1.7 17.3 17.3 82.7 1.18 15.5 33.6 22.4 77.6 1.18 19.5 36.8 36.8 63.2 0.60 26.5 60.1 40.07 59.93 0.60 17.2 54 54 46 0.425 25.5 85.6 57.07 42.93 0.425 12.9 66.9 66.9 33.1 0.30 19.9 105.5 70.34 29.66 0.30 6.6 73.5 73.5 26.5 0.15 23.2 128.7 85.8 14.2 0.15 13.5 87 87 13 0.075 16.8 145.5 97 3 0.075 4.9 91.9 91.9 8.1 Pan 4.0 150 100 0 Pan 8 100 100 0 Total 149.5 ≈ Σ= Total 99.9 ≈ Σ= 150 490.83 100 547.8 Mass loss during sieve analysis = 0.333% Mass loss during sieve analysis = 0.1% Fineness modulus= 4.90 Fineness modulus= 5.47 BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 18

INTERNSHIP REPORT

2018-2019

CALCULATIONS: Mass loss during test =

which should be always less than 2%

Cumulative % wt. retained (C) = Percentage passing or percentage finer = 100-C Coefficient of uniformity Cu = D60 / D10 Coefficient of curvature Cc = D302 /( D60 * D10) Percentage fine = ΣC/100  Where , D30 is the diameter corresponding to 30% finer in the particle-size distribution  D60 is the diameter corresponding to 60% finer in the particle-size distribution

100 100

100 100 100

Percentage passing in%

91.8

90 80

74.54 70 60 54.74 50

44 40 30 20 16.2 10 1.67 0.01

0.1

0 1

10

Particles size in mm

Figure 8: Grain size distribution of Bore hole no.BORE 1 HOLE NO. 1

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 19

INTERNSHIP REPORT

2018-2019 110 100 100

99

90

90.07 88.27

80 71

70 60

Percentage passing in%

57.47

50

48.47 43.8

40 30 26.24 20

10

8.47

0

0.01

0.1 1 Particles size in mm

Series1

10

Figure 9: Grain size distribution of Bore hole no. 02 BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 20

INTERNSHIP REPORT

2018-2019 110

100 98.73 95.13 90 87.93

80

70

60

59.93

50

42.93 40

Percentage passing in%

77.6

30

29.66

20 14.2 10

3 0.01

0 0.1

0 1

Particles size in mm

10 Series1

Figure 10: Grain size distribution of Bore hole no. 03 BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 21

INTERNSHIP REPORT

2018-2019

120 110 100 100

95.2 90

Percentage passing in%

84.4 82.7

80 70

63.2 60 50 46 40 33.1 30 26.5 20 13

10

8.1

0 0.01

0.1 1 Particles size in mm

Series1

10

Figure 11: Grain size distribution of Bore hole no. 04

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 22

INTERNSHIP REPORT

2018-2019

RESULTS:

CONTENTS

BH. NO 01

BH. NO 02

BH. NO 03

D10

0.13

0.085

0.24

0.1

D30

0.22

0.18

0.42

0.38

D60

0.5

0.7

1.3

1.12

Cu

=

=

= 3.84

= 8.23

= CC = 0.745

= = 0.545

BH. NO 04

=

=

= 5.416 = = 0.565

= 11.2 = = 1.29

A. The coefficient of uniformity for  Borehole No. 1: Cu = 3.84  Borehole No. 2: Cu = 8.23  Borehole No. 3: Cu = 5.416  Borehole No. 4: Cu = 11.2 B. The coefficient of uniformity for  Borehole No. 1: Cc = 0.745  Borehole No. 2: Cc = 0.545  Borehole No. 3: Cc = 0.565  Borehole No. 4: Cc = 1.29

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 23

INTERNSHIP REPORT

2018-2019

3) SPECIFIC GRAVITY OF SOIL DEFINITION: Specific gravity of soil solid is the ratio between the unit weight of the soil solid to the unit weight of the water. In other words it is the density of the soil solid relative to water. SIGNIFICANCE:  Higher the specific gravity higher is the value of strength.  This gives an idea about the extend of stability that the soil sample is able to offer for the proposed construction.  Specific gravity of soil plays an important role in the construction of road afoundation.

Figure 12:- Density bottle and weighing balance REFERENCE STANDARD: IS2720-PART 3-1980 AIM: To Determine Specific Gravity of Soil Solids by Density Bottle Method APPARATUS USED:  50ml density bottle with stopper  Oven (105 0 to 110 0C)  Weighing balance accuracy 0.001g PROCEDURE:  First and foremost job that is to be done is wash the density bottle and dry it in an oven at 105 0C to 100 0C. Cool it in the desiccators.  After the first step, Weigh the bottle, with stopper to the nearest 0.001g (M1).  Now take about 5 to 10g of the oven dried soil sample and transfer it the density bottle. Weigh the bottle with the stopper and the dry sample (M 2). BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 24

INTERNSHIP REPORT

2018-2019

 Add de-aired distilled water to the density bottle just enough to cover the soil. Shake gently to mix the soil and water.  Fill the water up to the lower portion of the lid and weigh it as M3.  Empty the density bottle and clean the surface and fill it with the only water till it reaches the lower portion of the lid and take the weight of bottle and the weight of the water as M4.  Calculate the specific gravity of the soil as per IS codes

M1= mass of empty Pycnometer. M2= mass of the Pycnometer with dry soil. M3= mass of the Pycnometer and soil and water. M4 = mass of Pycnometer filled with water only. G= Specific gravity of soils. TABULAR COLUMN: SL. NO.

Particulates

Trail 1

Trail 2

Trail 3

1.

Empty wt of bottle W1 ,gm

26

26

28

2.

Wt. of bottle + soil W2, gm

48

38

42

3.

Wt. of bottle + soil + water W3, gm

90

83

85

4.

Wt. of bottle + water W4,gm

76

76

76

5.

Specific gravity G

2.75

2.4

2.8

6.

Avg. specific gravity Gavg

2.65

STANDARD VALUES OF SPECIFIC GRAVITY: BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 25

INTERNSHIP REPORT

2018-2019

RESULTS: The average specific gravity og given soil sample is 2.65

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 26

INTERNSHIP REPORT

2018-2019

4) ATTERBERG’S LIMITS ANALYSIS – IS: 2720 PART 5 -1985 A. LIQUID LIMIT TEST OF SOIL BY CASAGRANDE’S METHOD: DEFINITION: It the minimum water at which the soil is in liquid state but has small shear strength which can be measured by standard available means. A liquid limit is the moisture content expressed as a percentage of the weight of oven-dried soil, at which soil changes from a plastic to a liquid state. SIGNIFICANCE:  These limits of soil are very important property of fine grained soil and its Value is used to classify fine grained soil and to calculate activity of clays, plasticity index of soil and toughness index of soil.  It also gives us information regarding the state of consistency of soil on site.  In addition, it also can be used to predict the consolidation properties of soil while calculating allowable bearing capacity & settlement of foundation REFERENCE STANDARD: IS 2720 (Part 5) 1985.

Figure 13: Casagrande's Apparatus AIM: To Determine the liquid limit of soil by casagrande method. APPARATUS USED:  Casagrande’s liquid limit device, BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 27

INTERNSHIP REPORT

2018-2019

 grooving tool,  glass plate,  425micron sieve,  spatula etc. PROCEDURE:  Soil sample passing 425 µ is air dried and Weight of soil sample taken for test = 120 g  Mix the sample thoroughly with required amount distilled water to form a uniform paste.  Place soil sample in cup, squeezed down and spread into position by spatula a depth of 1 cm at maximum thickness and cut a groove by using standard grooving tool  Turn the crank at the rate of 2 revolutions per second and count the no. of drops until the groove close through a length of 12mm  Take a representative slice of soil sample at right angle to the groove and find the moisture content  The operation is repeated for minimum of four times  Consistency that no. of drops required to close the groove shall be not less than 15 or more than 35  Plot curve log number of drops N and moisture content w and determine liquid limit(LL) at N = 25 CALCULATIONS:

Ww = W2-W3 g Ws = W3-W1 g Water content =

%

TABULAR COLUMN: BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 28

INTERNSHIP REPORT

LIQUID LIMIT

2018-2019

TRAIL-1

TRAIL-2

TRAIL-3

TRAIL-4

Wt. of empty cup(W1 g)

9

9

9

9

Wt. of wet soil+ cup(W2 g)

18

21

18

20

Wt. of dry soil+ cup(W3 g)

14

17

16

18

Wt. of water (Ww = W2-W3)g

4

4

2

2

Wt. of dry soil (Ws = W3-W1)g

5

8

7

9

(W= Ww/Ws)%

80

50

28.57

22.22

No. of blows

13

14

28

34

Water content in percentage

Liquid Limit(LL)= Results: The liquid limit of the given soil sample by casegrande’s method is 28%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 29

INTERNSHIP REPORT

2018-2019

90

80

80

70

Water content

60

50

50

40

30

28.57

22.22 20

10

0 0

5

10

15

20

25

30

35

40

No. of blows Figure 14: Curve representing Water content with respect to number of blows BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 30

INTERNSHIP REPORT

2018-2019

B. CONE PENETRATION TEST:

Figure 15:- Cone penetration apparatus and Sample REFERENCE STANDARD: IS 2720 (Part 5) 1985. AIM: To determine the liquid limit of the soil by cone penetration test APPARATUS USED:  Cone penetrometer,  flexible spatula,  glass plate,  weighing balance,  containers,  425 micron IS sieves etc. PROCEDURE:  Soil sample passing 425 µ is air dried  Weight of soil sample taken for test = 150 g  Mix the sample thoroughly with required amount distilled water and filled into the cylindrical cup  The penetrometer cone point is lowered and adjusted to just touch the surface of soil  Penetration of cone after 5 seconds is recorded BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 31

INTERNSHIP REPORT

2018-2019

 Test repeated by adjusting moisture content at least four times to

have values of the

range 14 to 28 mm  Take a representative soil sample at depression by cone and find the moisture content  Plot curve penetration and moisture content w and  Determine the liquid limit (LL) at penetration = 20mm TABULAR COLUMN: WATER CONTENT (W%)

DEPTH OF PENETRATION (mm)

10

17

12

22

14

28

16

34

Results: The liquid limit of the soil sample by cone penetration method = 15 %

18

water content

16

16

14

14

12

12

10

10

8 6 4 2 0 0

5

10

15

20

25

30

35

40

depth of penetration

C .PLASTIC LIMIT TEST OF SOIL: BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 32

INTERNSHIP REPORT

2018-2019

B. PLASTIC LIMIT: It is the constant defined as the lowest moisture content and expressed as a percentage of the weight of the oven dried soil at which the soil can be rolled into threads oneeighth inch or 3mm in diameter without the soil breaking into pieces, also the moisture content of a solid at which a soil changes from a plastic state to a semisolid state.

Figure 16: Plastic limit of the soil REFERENCE STANDARD: IS 2720 (Part 5) 1985. AIM: Determination of plastic limit of soil APPARATUS USED:  Glass plate,  425 micron sieve,

 vernier caliper etc. PROCEDURE:  Soil sample passing 425 µ is air dried  Weight of soil sample taken for test = 20 g  Mixed thoroughly with distilled water till it becomes plastic such that it can be easily moulded with fingers.  A ball shall be formed with about 8 g of plastic soil mass and then rolled into a thread of uniform diameter with fingers on glass plate  The rate of rolling is kept about 80 to 90 stroke per minute  Till the thread diameter of 3 mm without crumbling

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 33

INTERNSHIP REPORT

2018-2019

 The piece of crumbled soil thread shall be collected and used for determination of moisture content  The test is repeated for at least three portion of the sample taken and average of three to determine the plastic limit. TABULAR COLIMN:

PLASTIC LIMIT

TRAIL-1

TRAIL-2

TRAIL-3

Wt. of empty cup (W1 g)

8

8

9

Wt. of wet soil+ cup (W2 g)

17

19

16

Wt. of dry soil+ cup (W3 g)

16

18

14.7

Wt. of water (Ww= W2-W3)g

1

1

1.3

Wt. of dry soil (Ws= W3-W1)g

8

10

5.7

Water content in percentage (W=Ww/Ws)%

12.5

10

22.80

Avg. Water content =

= 15.1%

Results: plastic limit of the soil is 15.1%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 34

INTERNSHIP REPORT

2018-2019

5) COMPACTION OF SOIL DEFINITION: It is the process in which a stress applied to a soil causes densification as air is displaced from the pores between the soil grains or Soil compaction is defined as the method of mechanically increasing the density of soil. SIGNIFICANCE: 

Compaction increases the shear strength of the soil.



Compaction reduces the voids ratio making it more difficult for water to flow through soil. This is important if the soil is being used to retain water such as would be required for an earth dam.



Compaction can prevent the buildup of large water pressures that cause soil to liquefy during earthquakes.



In construction, this is a significant part of the building process. If performed improperly, settlement of the soil could occur and result in unnecessary maintenance costs or structure failure.

A) STANDARD COMPACTION (LIGHT COMPACT): It is the mechanical effort used to compact the soil by ramming with a 2.5kg hammer with the number of blows about 25 numbers and hammer is falling from the height of 310mm B) MODIFIED COMPACTIONION (HEAVY COMPACT): It is the mechanical effort used to compact the soil by ramming with a 4.5kg hammer with the number of blows about 56 numbers and hammer is falling from the height of 450mm REFERENCE STANDARD: IS 2720 PART 7-1980 FORMULAES:

Bulk density

Dry density

ρb =

ρd =

g/cc

g/cc

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 35

INTERNSHIP REPORT

2018-2019

A.STANDARD PROCTOR TEST – LIGHT COMPACTION- IS 2720 Part 7 – 1980 AIM: For determination of the relation between the water content and the dry density of soils using light compaction.

Figure 17: Mould and Hammer Apparatus APPARATUS USED: 

Cylindrical mould & accessories [volume = 1000cm3]



Rammer [2.6 kg]



Balance [1g accuracy]



Sieves [19mm]



Mixing tray



Trowel



Graduated cylinder [500 ml capacity]



Metal container

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Figure 18:- Leveling of the soil surface

Page 36

INTERNSHIP REPORT

2018-2019

PROCEDURE:  Take about 2.5 kg of soil passing through 19mm sieve in a mixing tray.  The mould with base plate attached is weighed to the nearest 1 gm (M 1). The extension collar is to be attached with the mould  Mix thoroughly with suitable amount of water depending on soil type  Soil sample is compacted in three layers  Rammer weight is 2.6 kg - Height of fall is 310 mm  Rate of blow is 25 blows per layer.  The extension is removed and the compacted soil is leveled off carefully to the top of the mould by means of a straight edge.  The soil is removed from the mould and a representative soil sample is obtained water content determination.  Weight of the mould and soil is recorded and moisture content is calculated further bulk and dry densities are calculated  Add suitable increments of water and test is continued at least five times  Plot the curve between water content and dry density and the optimum water content and maximum dry density is obtained. OBSERVATIONS AND CALCULATIONS:  Diameter of cylinder mould (d) = 10.2 cm  Height of the cylinder (h) = 12.5 cm 

Area of cylinder = 81.71 cm2



Volume of cylinder (V) = 1005.03 cm3

 Height of fall = 31cm  No. of blows = 25  Number of layers = 3  Empty weight of mould M1= 4148 gm  Type of soil = white field BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 37

INTERNSHIP REPORT SL.NO.

Particulates

2018-2019 Trail 1

Trail 2

Trail 3

1

Mass of mould + compacted soil M2 g

6090

6640

6132

2

Mass of compacted soil ( M2-M1)

1942

2492

1984

3

Water content w %

12

14

16

RESULTS:

PARTICULATES

TRAIL 1

TRAIL 2

TRAIL 3

= 1.932

= 2.47

= 1.97

= 1.72

= 2.16

= 1.5

Bulk density ρb g/cc

Dry density ρd g/cc

The maximum dry density = 2.14 g/cc The optimum moisture content of given soil sample is = 14 % CONCLUSION: The maximum dry density MDD of soil 2.14 g/cc with an optimum moisture content OMC of 14 % indicates after 14 % in adding more water there is no gain in strength of soil.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 38

INTERNSHIP REPORT

2018-2019

2.5 2.16

dry density in g/cc

2 1.72 1.5

1.5 Series1

1

0.5

0 0

2

4

6

8 10 12 14 16 water20:content in compaction % Figure Standard

18

20

4 3.5

Dry density in g/cc

3 2.5 2 Series1

1.5 1 0.5 0 0

2

4

6

8

10 12 14 16 Water content in %

18

20

22

24

Figure 19: Modified compaction BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 39

INTERNSHIP REPORT

2018-2019

B.MODIFIED PROCTOR TEST – HEAVY COMPACTION- IS 2720 Part 7 – 1980

Figure 21: MOULD AND RAMMER AIM: To determine moisture content and dry density relationship using heavy compaction or modified compaction method as per IS-2720-Part-8. APPARATUS USED:  Metal mould (volume = 1000 cm3)  Balance (capacity = 10 kg, least count = 1g)  Oven (105 to 1100C)  Sieve (19 mm)  Metal rammer (weight = 4.9 kg) PROCEDURE:  Dry the soil sample by exposing it to air or sun light.  Sieve the air dried soil through 19 mm sieve.  Add suitable amount of water with the soil and mix it thoroughly. For sandy and gravelly soil add 3% to 5% of water. For cohesive soil the amount of water to be added should be 12% to 16% below the plastic limit.  Weigh the mould with base plate attached to the nearest 1g. Record this weight as ‘W1’. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 40

INTERNSHIP REPORT SL.NO.

Particulates

2018-2019 Trail 1

Trail 2

Trail 3

Trail 4

Trail 5

 Attach the extension collar with the mould.  Compact the moist soil into the mould in five layers of approximately equal mass, each layer being given 56 blows, with the help of 4.9 kg rammer, dropped from a height of 450 mm above the soil. The blows must be distributed uniformly over the surface of each layer.  After completion of the compaction operation, remove the extension collar and level carefully the top of the mould by means of straightedge.  Weigh the mould with the compacted soil to the nearest 1 g. Record this weight as ‘W2’.  After weighing remove the compacted soil from the mould and place it on the mixing tray. Determine the water content of a representative sample of the specimen. Record the moisture content as ‘W  further bulk and dry densities are calculated  Add suitable increments of water and test is continued at least five times  Plot the curve between water content and dry density and the optimum water content and maximum dry density is obtained. OBSERVATIONS AND CALCULATIONS:  Diameter of cylinder mould (d) = 15 cm  Height of the cylinder (h) = 12.73 cm 

Area of cylinder = 176.31 cm2



Volume of cylinder (V) = 2250 cm3

 Height of fall = 45cm  No. of blows = 56  Number of layers = 5  Empty weight of mould M1 = 7766 gm  Type of soil = white field BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 41

INTERNSHIP REPORT

2018-2019

1

Mass of mould + compacted soil M2 g

9710

9835

9846

9857

9828

2

Mass of compacted soil ( M2-M1)

1944

2069

2080

2091

2062

3

Water content w %

14

16

18

20

22

RESULTS:

PARTICULATES

TRAIL 1

TRAIL 2

TRAIL 3

TRIAL 4

TRAIL 5

= 0.864

= 4.372

= 4.376

= 4.380

=4.368

= 0.757

= 3.768

= 3.708

= 3.65

= 3.58

Bulk density ρb g/cc

Dry density ρd g/cc

The maximum dry density = 3.75 g/cc The optimum moisture content of given soil sample is = 16 % CONCLUSION: The maximum dry density MDD of soil 3.75 g/cc with an optimum moisture content OMC of 14 % indicates after 16 % in adding more water there is no gain in strength of soil.

6) DIRECT SHEAR TEST BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 42

INTERNSHIP REPORT

2018-2019

DEFINITION: Shear is defined as the force that causes two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. Shear strength is the stress required to yield or fracture the material in the plane of material cross-section IMPORTANCE:  In many engineering problems such as design of foundation, retaining walls, slab bridges, pipes, sheet piling, the value of the angle of internal friction and cohesion of the soil involved are required for the design. Direct shear test is used to predict these parameters quickly.

 Shear characteristics are also important when characterizing the structural integrity of a bond between two surfaces. This bond could be a weld, an adhesive bond or a friction joint. In all of these cases, failure of the bond is primarily dependent on its shear strength, which can only be experimentally determined by a shear test.

Figure 22: Direct shear test apparatus REFERENCE STANDARD: IS: 2720-Part 13-1986 AIM: To determine the shear strength of a sandy soil specimen by direct shear test. APPARATUS USED:  Shear box, divided into two halves by a horizontal plane, and fitted with locking and spacing screws  Box container to hold the shear box  Base plate having cross grooves on its top surface BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 43

INTERNSHIP REPORT

2018-2019

 Grid plates, perforated, 2 Nos.  Porous stones, 6mm thick, 2 Nos.  Loading pad  Loading frame  Loading yoke  Proving ring, capacity 2kN.  Dial gauges, accuracy 0.01mm, 2 Nos.  Static or dynamic compaction devices.  Spatula PROCEDURE:  Shear box dimensions is measured, the box is set up by fixing its upper part to the lower part with clamping screws, and then a porous stone is placed at the base.  For undrained tests, a serrated grid plate is placed on the porous stone with the serrations at right angle to the direction of shear. For drained tests, a perforated grid is used over the porous stone.  An initial amount of soil is weighed in a pan. The soil is placed into the shear box in three layers and for each layer is compacted with a tamper. The upper grid plate, porous stone and loading pad is placed in sequence on the soil specimen.  The pan is weighed again and the mass of soil used is computed.  The box is placed inside its container and is mounted on the loading frame. Upper half of the box is brought in contact with the horizontal proving ring assembly. The container is filled with water if soil is to be saturated.  The clamping screws is removed from the box, and set vertical displacement gauge and proving ring gauge to zero.  The vertical normal stress is set to a predetermined value. For drained tests, the soil is allowed to consolidate fully under this normal load. (Avoid this step for undrained tests.) BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 44

INTERNSHIP REPORT

2018-2019

 The motor is started with a selected speed and shear load is applied at a constant rate of strain. Readings of the gauges are taken until the horizontal shear load peaks and then falls, or the horizontal displacement reaches 20% of the specimen length.  The moisture content of the specimen is determined after the test. The test is repeated on identical specimens under different normal stress values. CALCULATION 

The density of the soil specimen is calculated from the mass of soil and the volume of the shear box.



The dial readings are converted to the appropriate displacement and load units by multiplying with respective least counts.



Shear strains are calculated by dividing horizontal displacements with the specimen length, and shear stresses are obtained by dividing horizontal shear forces with the shear area.



The shear stress versus horizontal displacement is plotted. The maximum value of shear stress is read if failure has occurred, otherwise read the shear stress at 20% shear strain. The maximum shear stress versus the corresponding normal stress is plotted for each test, the cohesion and the angle of shearing resistance of the soil is determined from the graph.

Figure 23:- Direct Shear apparatus and Mould OBSERVATIONS: Soil density = 1.8 g/cc DIRECT SHEAR TEST

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 45

INTERNSHIP REPORT

2018-2019

Size of the specimen = 6 cm x 6 cm x 2 cm Area of the specimen = 36 cm

Proving ring least count LC= 0.2mm

2

Proving ring constant PRC= 0.26

Volume of the specimen = 72 cm3

Horizontal

Load

displacement

reading in E kN

reading in mm

cell Strain

Normal stress : 0.50 kg/cm2

Corrected area Ac =

Load

Stress

(PR x LC x

σ=

PRC) (Cm2)

(kN)

0.000

36.00

0.0000

0.000

0.027

0.008

36.29

0.0014

0.037

1.00

0.031

0.016

36.58

0.0016

0.042

1.50

0.035

0.025

36.92

0.0018

0.047

2.00

0.038

0.033

37.22

0.0019

0.050

2.50

0.026

0.041

37.53

0.0013

0.033

3.00

0.030

0.050

37.89

0.0015

0.038

3.50

0.033

0.058

38.21

0.0017

0.043

4.00

0.037

0.066

38.54

0.0019

0.048

4.50

0.038

0.075

38.91

0.0019

0.048

5.00

0.036

0.083

39.25

0.0018

0.044

5.50

0.037

0.091

39.60

0.0019

0.047

6.00

0.035

0.100

40.00

0.0018

0.044

6.50

0.039

0.108

40.35

0.0020

0.048

7.00

0.040

0.116

40.72

0.0020

0.048

7.50

0.044

0.125

41.14

0.0022

0.053

8.00

0.040

0.133

41.52

0.0022

0.051

8.50

0.036

0.141

41.90

0.0018

0.042

9.00

0.037

0.150

42.35

0.0019

0.044

)

(PR)

0.00

0.000

0.50

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 46

INTERNSHIP REPORT

2018-2019

DIRECT SHEAR TEST Size of the specimen = 6 cm x 6 cm x 2 cm

Proving ring least count LC= 0.2mm

Area of the specimen = 36 cm2

Proving ring constant PRC= 0.26

Volume of the specimen = 72 cm3

Normal stress : 1.00 kg/cm2

Horizontal

Load

displacement

reading

reading in mm

kN

cell Strain in

Corrected area Ac =

Load

Stress

(PR x LC x

σ=

PRC)

E (Cm2)

(kN)

0.000

36.00

0.0000

0.000

0.030

0.008

36.29

0.0015

0.039

1.00

0.056

0.016

36.58

0.0029

0.077

1.50

0.069

0.025

36.92

0.0035

0.092

2.00

0.076

0.033

37.22

0.0039

0.102

2.50

0.092

0.041

37.53

0.0047

0.122

3.00

0.100

0.050

37.89

0.0052

0.134

3.50

0.100

0.058

38.21

0.0052

0.133

4.00

0.095

0.066

38.54

0.0049

0.124

4.50

0.102

0.075

38.91

0.0053

0.133

5.00

0.086

0.083

39.25

0.0044

0.109

5.50

0.097

0.091

39.60

0.0050

0.123

6.00

0.113

0.100

40.00

0.0058

0.142

6.50

0.115

0.108

40.35

0.0059

0.143

7.00

0.117

0.116

40.72

0.0060

0.144

7.50

0.108

0.125

41.14

0.0056

0.133

8.00

0.143

0.133

41.52

0.0074

0.174

8.50

0.139

0.141

41.90

0.0072

0.168

9.00

0.128

0.150

42.35

0.0066

0.152

)

(PR)

0.00

0.000

0.50

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 47

INTERNSHIP REPORT

2018-2019

DIRECT SHEAR TEST Size of the specimen = 6 cm x 6 cm x 2 cm

Proving ring least count LC= 0.2mm

Area of the specimen = 36 cm2

Proving ring constant PRC= 0.26

Volume of the specimen = 72 cm3

Normal stress : 1.50 kg/cm2

Horizontal

Load

displacement

reading

reading in mm

kN

cell Strain in

Corrected area Ac =

Load

Stress

(PR x LC x

σ=

PRC)

E (Cm2)

(kN)

0.000

36.00

0.0000

0.000

0.058

0.008

36.29

0.0030

0.081

1.00

0.071

0.016

36.58

0.0036

0.096

1.50

0.091

0.025

36.92

0.0047

0.124

2.00

0.092

0.033

37.22

0.0047

0.123

2.50

0.101

0.041

37.53

0.0052

0.135

3.00

0.115

0.050

37.89

0.0059

0.152

3.50

0.118

0.058

38.21

0.0061

0.156

4.00

0.124

0.066

38.54

0.0064

0.162

4.50

0.122

0.075

38.91

0.0063

0.158

5.00

0.126

0.083

39.25

0.0065

0.162

5.50

0.125

0.091

39.60

0.0065

0.162

6.00

0.124

0.100

40.00

0.0064

0.156

6.50

0.126

0.108

40.35

0.0065

0.158

7.00

0.124

0.116

40.72

0.0064

0.154

7.50

0.130

0.125

41.14

0.0067

0.159

8.00

0.130

0.133

41.52

0.0067

0.158

8.50

0.128

0.141

41.90

0.0066

0.154

9.00

0.133

0.150

42.35

0.0069

0.159

)

(PR)

0.00

0.000

0.50

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 48

INTERNSHIP REPORT TEST NO.

2018-2019

NORMAL STRESS

MAX. STRESS

Kg/m2

Kg/m2

1

0.5

0.053

2

1.0

0.174

3

1.5

0.162

GRAPH: 0.2

0.18

0.16

MAX. STRESS kg/m2

0.14

0.12

0.1 Series1 0.08

0.06

0.04

0.02

0 0

0.5

1

1.5

2

NORMAL STRESS kg/m2

Figure 24: Direct shear

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 49

INTERNSHIP REPORT

2018-2019

From graph, Cohesion intercept C= 1.48 Angle of shearing resistance ϕ = 120 Shear strength s = c + σ tanϕ S1 = 1.48 + (0.053x tan 120) S1 = 1.49 kN/m2 S2 = 1.48 + ( 0.174 x tan 120) S2 = 1.516 kN/m2 S3 = 1.48 + ( 0.162 x tan 120) S3 = 1.514 kN/m2

RESULTS: Compressive strength of a given soil for 0.5 kN/m2 = 1.49 kN/m2 Compressive strength of a given soil for 1.00 kN/m2 = 1.516 kN/m2 Compressive strength of a given soil for 1.5 kN/m2 = 1.514 kN/m2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 50

INTERNSHIP REPORT

2018-2019

7) DIFFERENTIAL FREE SWELL INDEX OF A SOIL DEFINITION: It is the increase in volume of soil without any external constraint when subjected to submergence in water IMPORTANCE:  It is used to determine the silt content of soil particle by submerging the soil in water REFERENCE STANDARD: IS 2720-PART 40-1970

Figure 25:- Soil before and after 24hrs AIM: - To determine the increase in volume of a soil after 24 hrs. APPARATUS USED:  IS Sieve of size 425 micron  Oven  Balance with accuracy 0.01g  Graduated glass cylinder 2 number each of 100ml capacity strong PROCEDURE:  Take two specimens of 10g each of pulverized soil passing through 425 μ IS Sieve and oven-dry.  Pour each soil specimen into a graduated glass cylinder of 100ml capacity  Pour distilled water in one and kerosene oil in the other cylinder up to 100ml mark.  Remove entrapped air by gently shaking or stirring with a glass rod. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 51

INTERNSHIP REPORT

2018-2019

 Allow the suspension to attain the state of equilibrium (for not less than 24hours).  Final volume of soil in each of the cylinder should be read out. Free swell index where, Vd = volume of soil specimen read from the graduated cylinder containing distilled water. Vk = volume of soil specimen read from the graduated cylinder containing kerosene.

Particulates

Distilled water

kerosene

Initial volume

10

10

Final volume

14

13

Increase in volume

4

3

Free swell index

= 33.33% RESULT: The free swell index of a given soil sample = 33.33 %

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 52

INTERNSHIP REPORT

2018-2019

8) CBR (CALIFORNIA BEARING RATIO) DEFINITION: is the ratio of the force per unit area required to penetrate a soil mass with a standard circular piston of 50 mm dia, at the rate of 1.25 mm/min to that of force required to penetrate sample of compacted stone having CBR of 100%. IMPORTANCE:  Indian Road Congress (IRC) has standardized the guidelines for the design of flexible pavements based on CBR test (vide IRC-37) and this method is being followed for the design of flexible pavements for all the categories of roads in India.  The CBR rating was developed for measuring the load-bearing capacity of soils used for building roads. The CBR can also be used for measuring the load-bearing capacity of unimproved airstrips or for soils under paved airstrips. The harder the surface, the higher the CBR rating.

Figure 26: CBR TESTING MACHINE AND MOULD REFERENCE STANDARDS: IS 2720 (Part 16)-1973 AIM: Determination of California bearing ratio CBR of soil either in undisturbed or Remoulded condition BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 53

INTERNSHIP REPORT

2018-2019

APPARATUS USED: 

Compression machine



Steel Cutting collar, Spacer Disc



Surcharge weight, Split mould



Dial gauges and Proving ring



IS Sieves



Penetration Plunger



Timer, Vernier caliper



Sampling tube, Balance etc

PREPARATION SAMPLE The test may be performed (a) On undisturbed soil specimen (b) On remoulded soil specimen (a) On undisturbed specimen Undisturbed specimen is obtained by fitting to the mould, the steel cutting edge of 150 mm internal diameter and pushing the mould as gently as possible into the ground. When the mould is sufficiently full of soil, it shall be removed by under digging. The top and bottom surfaces are then trimmed flat so as to give the required length of specimen. (b) On remoulded Specimens The dry density for remoulding should be either the field density or if the subgrade is to be compacted, at the maximum dry density value obtained from the Proctor Compaction test. If it is proposed to carry out the CBR test on an unsoaked specimen, the moisture content for remoulding should be the same as the equilibrium moisture content which the soil is likely to reach subsequent to the construction of the road. If it is proposed to carry out the CBR test on a soaked specimen, the moisture content for remolding should be at the optimum and soaked under water for 96 hours. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 54

INTERNSHIP REPORT

2018-2019

Soil Sample – The material used in the remolded specimen should all pass through a 19 mm IS sieve. Allowance for larger material may be made by replacing it by an equal amount of material which passes a 19 mm sieve but is retained on a 4.75 mm IS sieve. This procedure is not satisfactory if the size of the soil particles is predominantly greater than 19 mm. The specimen may be compacted statically or dynamically. I. Compaction by Static Method The mass of the wet soil at the required moisture content to give the desired density when occupying the standard specimen volume in the mould is calculated. A batch of soil is thoroughly mixed with water to give the required water content. The correct mass of the moist soil is placed in the mould and compaction obtained by pressing in displacer disc, a filter paper being placed between the disc & soil. II. Compaction by Dynamic Method For dynamic compaction , a representative sample of soil weighing approximately 4.5 kg or more for fine grained soils and 5.5 kg or more for granular soil shall be taken and mixed thoroughly with water. If the soil is to be compacted to the maximum dry density at the optimum water content determined in accordance with light compaction or heavy compaction, the exact mass of soil required is to be taken and the necessary quantity of water added so that the water content of soil sample is equal to the determined optimum water content. The mould with extension collar attached is clamped to the base plate. The spacer disc is inserted over the base plate and a disc of coarse filter paper placed on the top of the spacer disc. The soil water mixture is compacted into the mould in accordance with the methods specified in light compaction test or heavy compaction test. PROCEDURE:  The mould containing the specimen with the base plate in position but the top face exposed is placed on the lower plate of the testing machine.  Surcharge weights, sufficient to produce an intensity of loading equal to the weight of the base material and pavement is placed on the specimen.  To prevent upheaval of soil into the hole of the surcharge weights, 2.5 kg annular weight is placed on the soil surface prior to seating the penetration plunger after which the remainder of the surcharge weight is placed. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 55

INTERNSHIP REPORT

2018-2019

 The plunger is to be seated under a load of 4 kg so that full contact is established between the surface of the specimen and the plunger.  The stress and strain gauges are then set to zero. Load is applied to the penetration plunger so that the penetration is approximately 1.25 mm per minute.  Readings of the load are taken at penetrations of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 4.0, 5.0, 7.5, 10.0 and 12.5 mm.  The plunger is then raised and the mould detached from the loading equipment. CALCULATION Load-Penetration curve: The load penetration curve is plotted taking penetration value on x-axis and Load values on Yaxis. Corresponding to the penetration value at which the CBR is desired, corrected load value is taken from the load-penetration curve and the CBR calculated as follows STANDARD LOAD USED IN CBR TEST: Penetration in mm

Standard load in kg

2.5

1370

5.0

2055

7.5

2630

10.0

3180

12.5

3600

California bearing ratio Where PT = Corrected unit (or total) test load corresponding to the chosen penetration curve, and PS = Unit (or total) standard load for the same depth of penetration as for PS taken from standard code OBSERVATIONS AND CALCULATIONS: BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 56

INTERNSHIP REPORT

2018-2019

CALIFORNIA BEARING RATIO( CBR)

SL.NO.

Particulates

Trail 1

Trail 2

1

Diameter of cylinder mould (d)

2

Height of the cylinder (h)

3

Area of cylinder

4

Volume of cylinder (V)

5

Height of fall

45cm

6

No. of blows

56

7

Number of layers

5

8

Type of compaction

Heavy compaction

9

Empty mass of mould, M1 g

7766

7766

10

Mass of mould + compacted soil M2 g

11658

11551

11

Mass of soil M2-M1

3892

3785

12

Water content w %

15

10

13

Length of soil cm

4.7

4.8

14

Bulk density g/cc

1.642

1.68

15

Dry density g/cc

1.42

1.52

16

Average water content

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

15 cm 12.73 cm 176.31 cm2 2250 cm3

12.5%

Page 57

INTERNSHIP REPORT Test : 1

2018-2019 Proving ring least count : 6.138

Condition : Unsoaked Dial guage reading (DGR)

Proving ring reading (PRR)

20

04

40

06

60

09

80

14

100

18

150

48

200

50

300

89

400

119

500

152

600

186

700

209

CALIFORNIA BEARING RATIO( CBR) Test : 2

Proving ring least count : 6.138

Condition : Unsoaked Dial guage reading (DGR)

Proving ring reading (PRR)

20

02

40

05

60

08

80

12

100

15

150

22

200

26

300

32

400

36

500

39

600

43

700

45

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 58

INTERNSHIP REPORT

2018-2019

250

Fro m 200

gra

LOAD IN kN

phs ,

150

Tes t 1:

100

2.5 mm

50

pen etra 0 0

1

2

3

4

5

6

7

tion

8

PENETRATION IN MM

=

Figure 28:CBR Test 1

70

50 45

45 43

40

39 36

LOAD IN kN

35 32

30 26

25 22

20 15

15 12

10 8 5

5 2

0 0

1

2

3

4

5

6

7

8

PENETRATION IN MM Figure 27: CBR Test 2 BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 59

INTERNSHIP REPORT

2018-2019

kN 5mm penetration = 150 kN

* 100 = 5.1%

CBR @ 2.5 mm =

CBR @ 5 mm =

* 100 = 7.3%

Test 2: 2.5mm penetration = 29 kN 5mm penetration = 39 kN

CBR @ 2.5 mm =

CBR @ 5 mm =

* 100 = 1.1% * 100 = 1.9%

Average CBR at 2.5 mm penetration = 3.1 % Average CBR at 5 mm penetration = 4.6 %

RESULTS: Test 1: Accepted CBR at 5mm penetration is 7 % Test 2: Accepted CBR at 5mm penetration is 2 %

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 60

INTERNSHIP REPORT

2018-2019

3.0. CONCRETE TECHNOLOGY

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 61

INTERNSHIP REPORT

2018-2019

3.A INTRODUCTION TO CONCRETE CONCRETE is made by mixing CEMENT WATER COARSE AND FINE AGGREGATES ADMIXTURES (if required).  The aim is to mix these materials in measured amounts to make concrete that is easy to: Transport, Place, Compact and finish and which will set and harden, to give a strong and durable product.  The amount of each material (i.e., cement, water and aggregates) affects the properties of hardened concrete.

a) CEMENT: The cement is the powder which forms a paste when it is mixed with water and this paste acts like glue and holds or bonds the aggregates together

b) AGGREGATES: Aggregates are of two basic types  COARSE: crushed rock, gravel or screenings.  FINE: fine and coarse sands and crusher fines.

c) WATER: Water is mixed with the cement powder to form a paste which holds the aggregates together like glue.

ADMIXTURES : Admixtures are mixed into the concrete to change or alter its properties, i.e., the time concrete takes to set and harden, or its workability.

PROPERTIES OF CONCRETE: The properties of concrete are its characteristics or basic qualities. The four main properties of concrete are:  Workability  Cohesiveness  Strength  Durability

A) WORKABILITY: It is the ease with which concrete can be placed, handled, compacted and finished as a concrete mix. A slump test can be used to measure the workability of concrete. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 62

INTERNSHIP REPORT

2018-2019

B) COHESIVENESS: Cohesiveness is how well concrete HOLDS TOGETHER when plastic.

C) STRENGTH AND DURABILITY: Well made concrete is a naturally strong and durable material. It is DENSE, reasonably WATERTIGHT, able to resist changes in TEMPERATURE, as well as wear and tear from WEATHERING.  Strength and durability in the hardened state is usually measured by the COMPRESSIVE STRENGTH using compression Test.  Well made concrete is very important to protect the steel in reinforced concrete.

CONCRETE HAS 3 DIFFERENT STATES:  Plastic  Setting  Hardening

A) PLASTIC STATE: When the concrete is first mixed it is like 'bread dough'. It is soft and can be worked or moulded into different shapes. In this state concrete is called PLASTIC. Concrete is plastic during placing and compaction. The most important properties of plastic concrete are workability and cohesiveness. A worker will sink into plastic concrete.

B) SETTING STATE:

Concrete then begins to stiffen. The

stiffening of concrete, when it is no longer soft, is called SETTING. Setting takes place after compaction and during finishing. Concrete that is sloppy or wet may be easy to place but will be more difficult to finish. A worker leaves footprints in setting concrete.

C) HARDENING STATE: After concrete has set it begins to gain strength and harden. Hardened concrete will have no footprints on it if walked on.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 63

INTERNSHIP REPORT

2018-2019

LABORTATORY TESTS ON CONCRETE There are two main tests to be done on concrete: 1. THE SLUMP TEST: It shows the workability of concrete. 2. THE COMPRESSION TEST: It shows the best possible strength concrete can reach in perfect conditions

1) COMPRESION TEST ON CONRETE CUBES DEFINITION: The compression strength of concrete is a measure of the concrete's ability to resist loads which tend to compress it. It consists of applying a compressive axial load to molded cubes at a rate which is within a prescribed range until failure occurs . IMPORTANCE:  Compressive strength results are used to determine that the concrete mixture meets the requirements of the specified strength  Strength is extremely important for any material and any construction project. You need to have the right amount of strength, in some cases no less and no more, to be able to accomplish the task. Since concrete is used in key places like foundations, flooring, it’s important that the concrete is strong enough to hold the weight.

Figure 29: Concrete cubes and Cylinder sample

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 64

INTERNSHIP REPORT

2018-2019

REFERENCE STANDARDS: IS 516-1959 AIM: Determination of compressive strength of cubic concrete specimens. APPARATUS USED:

 Compression testing machine  Curing tank  Weighing Balance  Trowel  Measuring cylinder  Tray etc. PROCEDURE  Representative samples of concrete shall be taken and used for casting cubes 15 cm x 15 cm x 15 cm or cylindrical specimens of 15 cm dia x 30 cm long.  The concrete shall be filled into the moulds in layers approximately 5 cm deep. It would be distributed evenly and compacted either by vibration or by hand tamping. After the top layer has been compacted, the surface of concrete shall be finished level with the top of the mould using a trowel; and covered with a glass plate to prevent evaporation.  The specimen shall be stored at site for 24± ½ h under damp matting or sack. After that, the samples shall be stored in clean water at 27±20C; until the time of test. The ends of all cylindrical specimens that are not plane within 0.05 mm shall be capped.  Just prior to testing, the cylindrical specimen shall be capped with sulphur mixture comprising 3 parts sulphur to 1 part of inert filler such as fire clay.  Specimen shall be tested immediately on removal from water and while they are still in wet condition.  The bearing surface of the testing specimen shall be wiped clean and any loose material removed from the surface. In the case of cubes, the specimen shall be placed in the machine in such a manner that the load cube as cast, that is, not to the top and bottom.  Align the axis of the specimen with the steel platen, do not use any packing.  The load shall be applied slowly without shock and increased continuously at a rate of approximately 140 kg/sq.cm/min until the resistance of the specimen to the increased load breaks down and no greater load can be sustained. The maximum load applied to the BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 65

INTERNSHIP REPORT

2018-2019

specimen shall then be recorded and any unusual features noted at the time of failure brought out in the report. CALCULATION Where P= Maximum applied load, (kg) A= Cross sectional area of cube, (mm2) COMPRESSIVE STRENGTH OF CONCRETE AT VARIOUS AGES AND GRADES:

Age

Sl. No

Grade of concrete

Age of concrete

Contact area mm2

Weight of specimen in kg

Load in kN (P)

Compressive strength in N/mm2

1

M25

28 days

22500

8.35

550

24.44

2

M25

28 days

22500

8.26

533

23.69

3

M25

28 days

22500

8.41

542

24.09

Strength per cent

Minimum compressive strength N/mm2 at 7 days

Specified characteristic compressive strength (N/mm2) at 28 days

1 day

16%

Grade of Concrete

3 days

40%

M15

10.0

15

M20

13.4

20

M25

16.7

25

M30

20.1

30

M35

23.5

35

M40

26.8

40

M45

30.1

45

7 days

67%

14 days

90%

28 days

100%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 66

INTERNSHIP REPORT

2018-2019

THE MINIMUM CUBE STRENGTH REQUIRED AS PER STANDARDS:

Figure 31: cube after test

Figure 30: Soaking of cubes in water

RESULTS:

Average compressive strength of concrete cubes = 24.07 N/mm2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 67

INTERNSHIP REPORT

2018-2019

INTRODUCTION TO CEMENT DEFINITION: Cement is a binder, a substance used in construction that sets and hardens and can bind other materials together.

CEMENT PRODUCTION:  Limestone and clay are quarried, crushed, stockpiled and ground separately. In the wet process, slurries are made and blended. However, this is uneconomical. In the dry process, the grinding is performed with dry materials but some water may be added to facilitate handling.  The ground and blended material is fed into a rotating inclined kiln. As the material slowly moves down the kiln, evaporation, calcinations, clinkering and cooling take place. (Clinkering is a heat treatment where partial melting  The clinker (dark porous nodules of 6-50 mm diameter) is further cooled with air or water. It is ground to a powder in a ball mill, along with a small amount of gypsum, to obtain Portland cement.

STORAGE OF CEMENT: Cement should be stored off the ground in a well-aired, clean, dry place. Wrapping the cement bags in plastic sheets gives extra protection, Bulk cement will normally be stored in silos.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 68

INTERNSHIP REPORT

2018-2019

TESTS ON CEMENT FIELD TESTING ON CEMENT:  Open the bag and take a good look at the cement, then it should not contain any visible lumps.  Color of cement should be greenish grey.  Should get cool feeling when thrusted.  When we touch the cement, it should give a smooth ¬ a gritty feeling.  When we throw the cement on a bucket full of water before it sinks the particles should flow.  When we make a stiff paste of cement & cut it with sharp edges & kept on a glass plate under water there won’t be any disturbance to the shape and should get strength after 24 hours.

LABORATORY TESTS ON CEMENT: The physical principal tests on cement are; 1) Consistency 2) Setting time 3) Soundness 4) Fineness 5) Compressive strength

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 69

INTERNSHIP REPORT

2018-2019

LABORATORY TESTS ON CEMENT 1) NORMAL CONSISTENCY OF CEMENT: DEFINITION: The standard consistency of a cement paste is defined as that consistency which will permit the vicat plunger to penetrate to a point 5 to 7mm from the bottom of the vicat mould. IMPORTANCE: The basic aim is to find out the water content required to produce a cement paste of standard consistency as specified by the IS: 4031 (Part 4) – 1988.  This test helps to determine water content for other tests like initial and final setting time, soundness & compressive strength.  Consistency refers to the relative mobility of a freshly mixed cement paste or mortar or its ability to flow. For a mortar the standard consistency is measured by flow table test.  Generally the normal consistency for OPC ranges from 26 to 33%.

Figure 32: Vicat apparatus BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 70

INTERNSHIP REPORT

2018-2019

REFERENCE STANDARDS: IS4031-PART 4- 1988. AIM: The basic aim is to find out the water content required to produce a cement paste of standard consistency. PRINCIPLE: The principle is that standard consistency of cement is that consistency at which the Vicat plunger penetrates to a point 5-7mm from the bottom of Vicat mould. APPARATUS USED:  Vicat apparatus conforming to IS: 5513 1976,  Balance, whose permissible variation at a load of 1000g should be +1.0g,  Gauging trowel conforming to IS: 10086 1982. PROCEDURE:  Weigh approximately 400g of cement and mix it with a weighed quantity of water. The time of gauging should be between 3 to 5 minutes.  Fill the Vicat mould with paste and level it with a trowel.  Lower the plunger gently till it touches the cement surface.  Release the plunger allowing it to sink into the paste.  Note the reading on the gauge.  Repeat the above procedure taking fresh samples of cement and different quantities of water until the reading on the gauge is 5 to 7mm. CALCULATION: Calculate percentage of water (p) by weight of dry cement required to prepare cement paste of standard consistency by following formula , and express it to the first place of decimal .

Where W = quantity of water added C = quantity of cement used OBSERVATIONS: Weight of cement taken = 400gm

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 71

INTERNSHIP REPORT Trail No.

Water added in ml

2018-2019 Percentage of water

Consistency

added 1

112

28

10

2

114

28.5

8

3

116

29

7

RESULTS: The normal consistency of cement P = 29%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 72

INTERNSHIP REPORT

2018-2019

2) SETTING TIME TEST ON CEMENT: DEFINITION: The time at which the cement paste loses its plasticity is termed as initial setting time and the time at which the cement paste becomes hard mass is termed as the final setting time. IMPORTANCE:  It is very important to know the setting times. Knowing the initial setting time is important in estimating free time for Mixing, transporting, placing, compaction and shaping of cement paste Knowledge of final setting time of cement is necessary as well.  After initial setting of cement, concrete starts gaining strength and harden so we have to know approximate final setting time of cement. Final setting time also

Figure 33: Vicat Apparatus and needle

affects the strength and durability of concrete REFERENCE STANDARDS: IS 4031- PART 5-1988 PROCEDURE TO DETERMINE INITIAL AND FINAL SETTING TIME OF CEMENT  Prepare a cement paste by gauging the cement with 0.85 times the water required to give a paste of standard consistency.  Start a stop-watch, the moment water is added to the cement.  Fill the Vicat mould completely with the cement

Figure 34: Initial and final Setting time needles

paste gauged as above, the mould resting on a non-porous plate and smooth off the surface of the paste making it level with the top of the mould.  The cement block thus prepared in the mould is the test block.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 73

INTERNSHIP REPORT

2018-2019

A) INITIAL SETTING TIME  Place the test block under the rod bearing the needle.  Lower the needle gently in order to make contact with the surface of the cement paste and release quickly, allowing it to penetrate the test block.  Repeat the procedure till the needle fails to pierce the test block to a point 5.0 to 5.5 mm measured from the bottom of the mould.  The time period elapsing between the time, water is added to the cement and the time, the needle fails to pierce the test block by 5.0 to 5.5 mm measured from the bottom of the mould, is the initial setting time. B) FINAL SETTING TIME  Replace the above needle by the one with an annular attachment.  The cement should be considered as finally set when, upon applying the needle gently to the surface of the test block, the needle makes an impression therein, while the attachment fails to do so.  The period elapsing between the time, water is added to the cement and the time, the needle makes an impression on the surface of the test block, while the attachment fails to do so, is the final setting time. OBSERVATIONS AND CALCULATIONS:

Setting time

Wt. of cement

Percentage of water added

ml of water added

Time @ water added

Time @ set

Setting time

Initial setting time

400g

24.65 %

98.6

10:00 am

12:20 pm

140 min

Final setting time

400g

24.65%

98.6

10:00 am

2:04 pm

244 min

RESULTS: Initial setting time of cement = 140 min Final setting time of cement = 244 min

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 74

INTERNSHIP REPORT

2018-2019

3) COMPRESSIVE STRENGTH OF CEMENT: DEFINITION: Compressive strength is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to tensile strength, which withstands loads tending to elongate. IMPORTANCE:  Concrete gains strength with time after casting. It takes much time for concrete to gain 100% strength and the time for same is still unknown. The rate of gain of concrete compressive strength in higher during the first 28 days of casting and then it slows down.  Strength is extremely important for any material and any construction project. You need to have the right amount of strength, in some cases no less and no

Figure 35: Mould Apparatus

more, to be able to accomplish the task. REFERENCE STANDARDS: IS 4031- PART 6- 1988 AIM: To determine the Compressive Strength of cement PRINCIPLE: Compressive strength of cement is determined by compressive strength test on mortar cubes compacted by means of a standard vibrating machine. Standard sand (IS:650) is used for the preparation of cement mortar. The specimen is in the form of cubes 70.6mmx70.6mmx70.6mm. APPARATUS USED:  Cube mould of size 70.6x70.6x70.6mm Figure 36: Cement block under UTM

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 75

INTERNSHIP REPORT

2018-2019

 Vibration machine  Balance  Tray, trowel, poking rod, Measuring cylinder etc. Environmental Conditions Temperature

27 ± 20 C

Humidity

65 ± 5 %

PROCEDURE:  Take 200 g of cement and 600 g of standard sand and mix them dry thoroughly.  Add [(P/4)+3] of water (where P is % of water required for preparing paste of standard consistency) to the dry mix of cement and sand and mix thoroughly for a minimum of 3 minutes and maximum of 4 minutes to obtain a mix of uniform color. If even in 4 minutes uniform color of the mix is not obtained reject the mix and mix fresh quantities of cement, sand and water to obtain a mix of uniform color.  Place the thoroughly cleaned and oiled (on interior face) mould on the vibrating machine and hold it in position by clamps provided on the machine for the purpose.  Fill the mould with entire quantity of mortar using a suitable hopper attached to the top of the mould for facility of filling and vibrate it for 2 minutes at a specified speed of 12000±400 per minute to achieve full compaction.  Remove the mould from the machine and keep it in a place with temp of 27±2 0C and relative humidity of 90% for 24 hours.  At the end of 24 hrs remove the cube from the mould and immediately submerge in fresh clean water. The cube be taken out of the water only at the time of testing.  Prepare at least 6 cubes in the manner explained above.  Place the test cube on the platform of a compressive testing machine without any packing between the cube and the plates of the testing machine.  Apply the load steadily and uniformly, starting from zero at a rate of 35 N/mm 2/minute.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 76

INTERNSHIP REPORT

2018-2019

CALCULATION:

Compressive Strength = P/A Where, P=Maximum load applied to the cube. (N) A=Cross sectional area (Calculated from the mean dimensions) (mm 2) 

Compressive strength is reported to the nearest 0.5 N/mm 2.



Specimens that are manifestly faulty, or that give strengths differing by more than 10% from the average value of all the test specimen should not be considered.



Test three cubes for compressive strength for each period of curing.

Sl. No

1

Type of

Age of

Contact

Load in

Compressive

cement

concrete

area mm2

kN (P)

strength in N/mm2

156.3

31.36

162.3

32.56

160.7

32.24

OPC 53 Grade

3 Days

4984

REUSLTS: 1) Average compressive strength of specimen for 3 days of curing = 32.05 N/mm2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 77

INTERNSHIP REPORT

2018-2019

3.B. INTRODUCTION TO AGGREGATES DEFINITION:  Construction aggregate, or simply "aggregate", is a broad category of coarse to medium grained particulate material

used in construction, including sand, gravel, crushed

stone, slag, recycled concrete and geosynthetic aggregates.  In other words coarse aggregates are defined as uncrushed gravel or stone which is the result of natural disintegration and crushed grave or stone are usually called the coarse aggregates.

TYPES OF AGGREGATES:  Coarse aggregates  Fine aggregates  All In aggregates

I) COARSE AGGREGATES:

Figure 37: Coarse Aggregates Sample

Coarse aggregates are an integral part of many construction applications, sometimes used on their own, such as a granular base placed under a slab or pavement, or as a component in a mixture, such as asphalt or concrete mixtures. Coarse aggregates are generally categorized as rock larger than a standard No. 4 sieve (3/16 inches) and less than 2 inches.

II) FINE AGGREGATE It is the aggregate most of which passes 4.75 mm IS sieve and contains only so much coarser as is permitted by specification. According to source fine aggregate may be described as:  Natural Sand– it is the aggregate resulting from the natural disintegration of rock and which has been

Figure 38: Fine Aggregate Sample

deposited by streams or glacial agencies

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 78

INTERNSHIP REPORT

2018-2019

 Crushed Stone Sand– it is the fine aggregate produced by crushing hard stone.  Crushed Gravel Sand– it is the fine aggregate produced by crushing natural gravel.

III) ALL IN AGGREGATE It is the aggregate composed of both fine aggregate and coarse aggregate. According to size All-in-aggregate is described as all-in-aggregates of its nominal size, i.e. 40mm, 20mm etc. For example, all in aggregate of nominal size of 20mm means an aggregate most of which passes through 20 mm IS sieve and contains fine aggregates also.

Figure 39: All In Aggregate Sample

COARSE AGGREGATES SHAPES OF PARTICLES 1. ROUNDED AGGREGATES are preferred in concrete roads (rigid pavements) as the workability of concrete increases due to the less friction between the surfaces. 2. ANGULAR SHAPE of the particles is desirable in granular base coarse (flexible pavement) due to better interlocking and increased stability. 3. FLAKY SHAPE: A flaky particle is the one whose least dimension (thickness) is than 0.6 times the mean size. These are the materials of which the thickness is small as compared to the other two dimensions. Limit of flaky particles in the mixes is 30%. If the flaky particles are greater than 30% then the aggregate is considered undesirable for the intended use. 4. ELONGATED SHAPE: These are the particles having length considerably larger than the other two dimensions and it is the particle whose greater dimension is 1.8 times its mean size. Limit of elongated particles in the mixes is 45%. Thus, if the elongated particles are greater than 45%, then the aggregate is considered undesirable for the intended use. Flaky and Elongated particles are considered as a source of weakness

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 79

INTERNSHIP REPORT

2018-2019

LABORATORY TESTS ON COARSE AGGREGATES The following tests on coarse aggregates are conducted in laboratory 1) Sieve analysis 2) Bulk density (Loose and Rodded) 3) Flakiness and elongation index 4) Water absorption 5) Aggregate impact value 6) Aggregate crushing value 7) Los Angeles abrasion resistance 8) Determination of 10% Fines value

1) SIEVE ANALYSIS OF COARSE AGGREGATES DEFINITION: Grading refers to the determination of the particle-size distribution for aggregate. Grading limits and maximum aggregate size are specified because grading and size affect the amount of aggregate used as well as cement and water requirements, workability, pumpability and durability of concrete.

Figure 40: IS Sieve sets and Aggregate Sample

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 80

INTERNSHIP REPORT

2018-2019

IMPORTANCE:  If the water-cement ratio is chosen correctly, a wide range in grading can be used without a major effect on strength.  When gap-graded aggregate are specified, certain particle sizes of aggregate are omitted from the size continuum. Gap-graded aggregate are used to obtain uniform textures in exposed aggregate concrete.  Close control of mix proportions is necessary to avoid segregation. REFENCE STANDARDS: IS 2386-PART 1-1963 AIM: Determination of particle size distribution of coarse aggregates by sieve analysis APPARATUS USED:  IS Sieves set of size 63mm, 40mm, 20mm, 16mm, 12.5mm, 10mm, 4.75mm and pan  Balance  Sieve shaker  Tray PROCEDURE:  The sample shall be brought to an air-dry condition before weighing and sieving. This may be achieved either by drying at room temperature or by heating at a temperature of 100‖ to 110°C. The air-dry sample shall be weighed and sieved successively on the appropriate sieves starting with the largest. Care shall be taken to ensure that the sieves are clean before use.  Each sieve shall be shaken separately over a clean tray until not more than a trace passes, but in any case for a period of not less than two minutes. The shaking shall be done with a varied motion, backward sand forwards, left to right, circular clockwise and anticlockwise, and with frequent jarring, so that the material is kept moving over the sieve surface in frequently changing directions.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 81

INTERNSHIP REPORT

2018-2019

 Material shall not be forced through the sieve by hand pressure. Lumps of fine material, if present, may be broken by gentle pressure with fingers against the side of the sieve.  On completion of sieving, the material retained on each sieve, together with any material

SIEVE ANALYSIS OF COARSE AGGREGATES Weight of aggregates taken = 5kg = 5000g Sieve dia. mm

Wt. of sieve + Wt. of

% Wt. of aggregates retained

Cum. % retained in %

% passing

(C)

(100-C)

cleaned from the mesh, shall be weighed. OBSERVATIONS AND CALCULATIONS:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 82

INTERNSHIP REPORT

2018-2019

aggregate retained in g 63

0

0

0

100

40

0

0

0

100

20

593

11.86

11.86

88.1

16

2331

46.62

58.48

41.5

12

1595

31.9

90.38

9.6

10

391

7.82

98.2

1.8

4.75

35

0.7

98.9

1.1

Pan

55

1.1

100

0.0

total

5000

ΣC = 342.1

Fineness modulus

=

= 3.421

RESULTS: The fineness modulus of coarse aggregate = 3.4

2) SHAPE TEST OF AGGREGATES (FLAKINESS INDEX AND ELONGATION INDEX) DEFINITION: a) FLAKINESS INDEX: The flakiness index of an aggregate is the percentage by weight of particles in it whose least dimension ( thickness ) is less than three-fifths of their mean dimension.. b) ELONGATION INDEX: The elongation index of an aggregate is the percentage by weight of particles whose greatest dimension ( length ) is greater than one and four-fifths BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 83

INTERNSHIP REPORT

2018-2019

times their mean dimension. IMPORTANCE:  Particle shape and surface texture influence the properties of freshly mixed concrete more than the properties of hardened concrete.  Rough-textured, angular, and elongated particles require more water to produce workable concrete than smooth, rounded compact aggregate. Consequently, the cement content must also be increased to maintain the water-cement ratio. Generally, flat and elongated particles are avoided or are limited to about 15 % by weight of the total aggregate. REFERENCE STANDARDS: IS 2386- PART 1- 1963 AIM: Determination of Flakiness index and Elongation index of coarse aggregates APPARATUS USED:  Metal guage  Balance  Sieves 63mm, 40mm, 20mm, 16mm, 12.5mm, 10mm, 4.75mm and pan etc a) FLAKINESS INDEX VALUE: PROCEDURE:  The sample is sieved through IS sieve specified in Table shown below.  Dimension of Thickness and Length Gauge  A minimum of 200 pieces of each fraction is taken and weighed.  In order to separate flaky materials, each fraction is then gauged individually for thickness on a thickness gauge.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 84

INTERNSHIP REPORT

2018-2019

 The total amount of flaky material passing the thickness gauge is weighed to an accuracy of 0.1% of the weight of sample. OBSERVATIONS AND CALCULATIONS: Weight of aggregates taken = 5000 g SL.NO

Sieve size in mm

Wt. passing g

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

% Elongation index

Page 85

INTERNSHIP REPORT

2018-2019

1

25 – 20

66

1.32

2

20 – 16

100

2

3

16 – 12

49

0.98

4

12 – 10

11

0.22

5

10 – 6.3

0

0

6

total

226

4.52

b) ELONGATION INDEX VALUE

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 86

INTERNSHIP REPORT

2018-2019

PROCEDURE  The sample

is

sieved through

IS

sieve specified in Table shown below.  A minimum of 200 pieces of each fraction is taken and weighed.  In order to separate elongated materials, each fraction is then gauged individually for length in the length gauge.  The pieces of aggregate from each fraction tested which could not pass through the specified gauge length with its long sides elongated are collected separately to find the total weight of aggregate retained on the length gauge from each fraction.  The total amount of elongated material retained by the length gauge is weighed to an accuracy of 0.1% of the weight of sample Weight of aggregates taken = 5000 g Sl. No

Sieve size in mm

Wt. passing g

% Elongation index

1 2 3 4 5 6

25 – 20 20 – 16 16 – 12 12 – 10 10 – 6.3 total

0 229 445 249 0 923

0 4.58 8.9 4.98 0 18.46

RESULTS: Flakiness index of given sample of coarse aggregates is 4.52 % Elongation index of given sample of coarse aggregates is 18.46%

3) BULK DENSITY OF COARSE AGGREGATES (LOOSE AND RODDED) BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 87

INTERNSHIP REPORT

2018-2019

DEFINITION: The bulk density or unit weight of an aggregate is the mass or weight of the aggregate that required to fill a container of a specified unit volume. IMPORTANCE:  If we know the bulk density of the aggregate material then we can easily determine the mass required to fill a unit volume container.  Bulk density also indicates the percentage of voids present in the aggregate material. This percentage of voids affects the grading of the aggregates which is important in high strength concrete.  Bulk density also indicates the compactive effort required to compact the concrete. REFERENCE STANDARDS: IS 2386-PART 3-1963

Figure 41: Mould and specimen AIM: Determination of bulk density of coarse aggregates

APPARATUS USED:  Cylindrical mould of capacity 15 liter, BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 88

INTERNSHIP REPORT

2018-2019

 Tamping rod of 16 cm diameter and 60 cm height,  Weighing balance accurate to 1gm and other accessories. LOOSE BULK DENSITY Loose bulk density can be determined by filling the container with dried aggregates until it overflows from the container. Now level the top surface of container by rolling a rod on it. After that, weight the aggregate mass that is inside the container and divide it by the volume of container. This will give you the bulk density of the loose aggregates. COMPACTED BULK DENSITY Compacted bulk density can be determined by filling the container in three layers and tamped each layer with a 16mm diameter rounded nosed rod. After filling in three layers now leveled the top surface and evaluate compacted bulk density by using the same expression as for loose bulk density. A. PROCEDURE FOR COMPACTED BULK DENSITY  Measure the volume of the cylindrical metal measure by pouring water into the metal measure and record the volume “V” in litre.  Fill the cylindrical metal measure about one-third full with thoroughly mixed aggregate and tamp it 25 times using tamping bar.  Add another layer of one-third volume of aggregate in the metal measure and give another 25 strokes of tamping bar.  Finally fill aggregate in the metal measure to over-flowing and tamp it 25 times.  Remove the surplus aggregate using the tamping rod as a straightedge.  Determine the weight of the aggregate in the measure and record that weight “W” in kg.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 89

INTERNSHIP REPORT

2018-2019

B. PROCEDURE FOR LOOSE BULK DENSITY  Measure the volume of the cylindrical metal measure by pouring water into the metal measure and record the volume “V” in litre.  Fill the cylindrical measure to overflowing by means of a shovel or scoop, the aggregate being discharged from a height not exceeding 5 cm above the top of the measure  Level the top surface of the aggregate in the metal measure, with a straightedge or tamping bar.  Determine the weight of the aggregate in the measure and record the weight “W” in kg. STANDARD DIMENSIONS OF CLINDER :

Maximum nominal size of aggregates

Capacity of cylinder in litres

Inside diameter in cm

Inside height in cm

Minimum Thickness of metal in mm

4.75 mm

3

15

17

3.15

4.74 to 40 mm

15

25

30

4.00

Over 40 mm

30

35

31

5.00

OBSERVATIONS AND CALCULATIONS: unit weight or bulk density = W/V Where, W = Weight of aggregate in cylindrical metal measure, kg V = Volume of cylindrical metal measure, litre = 15 litres

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 90

INTERNSHIP REPORT

2018-2019

OBSERVATIONS AND CALCULATIONS:

Size of sieve in weight in kg

Bulk density in kg/litre

mm SL. NO

(M/V)

Loose bulk density

20 mm

21.18

1.412

Compacted bulk density

20mm

23.02

1.535

RESULTS: Bulk density of loose aggregates 1412 kg/m3 Bulk density of compaction aggregates 1535 kg/m3

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 91

INTERNSHIP REPORT

2018-2019

5) WATER ABSORPTION TEST OF COARSE AGGREGATES ( SPECIFIC GRVITY OF AGGREGATS ) DEFINITION:  SPECIFIC GRAVITY is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. It is the measure of strength or quality of the specific material. Aggregates having low specific gravity are generally weaker than those with higher specific gravity values.  WATER ABSORPTION is the ratio of weight of water absorbed to the weight of dry sample expressed as a percentage. It will not include the amount of water

Figure 42: Container and water tank

adhering to the surface of the particles.  SATURATED SURFACE DRY (S.S.D.) CONDITION is the condition related with the aggregate particles in which the permeable pores of the aggregate particles are filled with water but without free water on the surface of the particles. IMPORTANCE:  It is important to determine the properties of concrete made from such aggregates.  It is used for the calculation of the volume occupied by the aggregates in various mixes and generally it ranges from 2.5 to 3.  Smaller the number of pores, higher will be the specific gravity hence more will be the bond strength and more concrete strength.  Water absorption is a measure of porosity of aggregates and its resistance to frost action. Higher water absorption means more pores hence aggregate will be the considered as weak.  Water absorption value ranges from 0.1 – 2.0% for aggregate normally used in roads surfaces.  Aggregates with water absorption up to 4.0% are acceptable in base coarse. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 92

INTERNSHIP REPORT

2018-2019

REFERENCE STANDARDS: IS 2386 -Part 3 -1963 AIM: For determination of specific gravity & water absorption of aggregates. APPARATUS USED: 

Wire basket



Oven (1500c)



Container for filling water and suspending the basket and an air tight container



Balance[0-10 kg]



Shallow tray & absorbent clothes.

PREPARATION OF SAMPLE The sample to be tested is separated from the bulk by quartering or by using sample divider. PROCEDURE  About 2kg of the aggregate sample is washed thoroughly to remove fines, drained and then placed in the wire basket and immersed in distilled water at a temperature between 22 to 320C with a cover of at least 50 mm of water above the top of the basket  Immediately after the immersion the entrapped air is removed from the sample by lifting the basket containing it 25 mm above the base of the tank and allowing it to drop 25 times at the rate of about one drop per second. The basket and the aggregate should remain completely immersed in water for a period of 24±0.5 hours afterwards.  The basket and the sample are then weighed while suspended in water at a temperature of 22 to 320C. The weight is noted while suspended in water (W1) g.  The basket and the aggregate are then removed from water and allowed to drain for a few minutes, after which the aggregates are transferred to one of the dry absorbent clothes.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 93

INTERNSHIP REPORT

2018-2019

 The empty basket is then returned to the tank of water, jolted 25 times and weights in water (W2) g.  The aggregates placed in the dry absorbent clothes are surface dried till no further moisture could be removed by this clothe.  Then the aggregate is transferred to the second dry cloth spread in a single layer, covered and allowed to dry for at least 10 minutes until the aggregates are completely surface dry. 10 to 60 minutes drying may be needed. The surface dried aggregate is then weighed W3 g.  The aggregate is placed in a shallow tray and kept in an oven maintained at a temperature of 1100C for 24 hours. It is then removed from the oven, cooled in air tight container and weighed W4 g. OBSERVATIONS AND CALCULATION Weight of saturated aggregate suspended in water with basket A2 = 1867g Weight of basket suspended in water A1= 674 g Weight of saturated aggregate in water (A = A2 - A1) g = Ws = 1193g Weight of saturated surface dry aggregate in air B = 1939g Weight of water equal to the volume of the aggregate D = (B - A) = 746g Weight of oven dried aggregates C = 1932 g Specific gravity =

Water absorption =

=

= 2.59

=

= 0.36 %

RESULTS: The water absorption of given coarse aggregates is 0.36% The specific gravity of given coarse aggregates = 2.59

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 94

INTERNSHIP REPORT

2018-2019

5) AGGREGATE IMPACT VALUE DEFINITION: The ‘aggregate crushing value’ gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load. The property of a material to resist impact is known as toughness. The toughness is determined by aggregate Impact test. The aggregate impact value shall not exceed 45% by weight for aggregates used for concrete other than for wearing surface and 30% by weight for concrete for wearing surfaces, such as runways, roads and pavements, IMPORTANCE:  Due to movement of vehicles on the road the aggregates are subjected to impact resulting in their breaking down into smaller pieces.  The aggregates should therefore have sufficient toughness to resist their disintegration due to impact. This characteristic is measured by impact value test.  The aggregate impact value is a measure of resistance to sudden impact or shock, which may differ from its resistance to gradually applied compressive load. REFERENCE STANDARDS: IS 2386-Part IV--1963 AIM: Determination of the aggregate impact value of coarse aggregate, which passes 12.5mm. IS sieve and retained on 10mm. IS sieve. APPARATUS USED: 

Aggregate Impact Test Machine



Sieves (12.5mm,10mm)



Cylindrical metal measure



Tamping Rod



Balance (0-10kg)



Oven(1500c)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Figure 43: Impact Testing machine

Page 95

INTERNSHIP REPORT

2018-2019

PREPARATION OF TEST SAMPLE Test sample consist of aggregate passing a 12.5mm IS sieve and retained on a 10mm IS sieve. The aggregate to be tested is dried in oven for a period of not less than 4hours. PROCEDURE  The cylindrical steel cup is filled with 3 equal layers of aggregate and each layer is tamped 25 strokes by the rounded end of tamping rod and the surplus aggregate struck off, using the tamping rod as a straight edge.  The net weight of aggregate in the cylindrical steel cup is determined to the nearest gram (WA) and this weight of aggregate is used for the duplicate test on the same material.  The cup is fixed firmly in position on the base of the machine and the whole of the test sample is placed in it and compacted by a single tamping of 25 strokes of tamping rod.  The hammer is raised until its lower face is 380 mm. above the upper surface of the aggregate in the cup, and allowed to fall freely onto the aggregate 15 times, each being delivered at an interval of not less than one second.  The crushed aggregate is removed from the cup and sieved on 2.36 mm. IS sieve until no further significant amount passes in one minute.  The fraction passing the sieve is weighed to an accuracy of 0.1 g (WB) CALCULATIONS:

Aggregate impact Value

Classification of aggregates using Aggregate Impact Value is as given below:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 96

INTERNSHIP REPORT

2018-2019 Classification

Aggregate Impact Value <20%

Exceptionally Strong

10 – 20%

Strong

20-30%

Satisfactory for road surfacing

>35%

Weak for road surfacing

OBSERVATIONS AND CALCULATIONS:

Trails

Sieve size

Wt. retained Passing weight Total wt gm % of impact in gm

in gm (P)

(T)

(P/T)

Trail 1

2.36mm

273

70

343

20.40

Trail 2

2.36mm

281

69

350

19.71

Avg. rate of impact =

= 20.05%

RESULTS: The aggregate impact value is 20.05 % CONCLUSION: The aggregates used in wearing surfaces should have the aggregate impact value less than 30% And for buildings etc it should not more than 45%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 97

INTERNSHIP REPORT

2018-2019

6) AGGREGATE CRUSHING VALUE DEFINITION: Coarse aggregate crushing value is the percentage by weight of the crushed material obtained when test aggregates are subjected to a specified load under standardized conditions. The aggregate impact value shall not exceed 45 percent by weight for aggregates used for concrete other than for wearing surfaces and 30 percent by weight for concrete for wearing surfaces, such as runways, roads and pavements. IMPORTANCE:  Aggregate crushing value is a numerical index of the strength of the aggregate and it is used in construction of roads and pavements.  Crushing value of aggregates indicates its strength. Lower crushing value is recommended for roads and pavements as it indicates a lower crushed fraction under load and would give a longer service life and a more economical performance.  The aggregates used in roads and pavement

construction

must

Figure 44: Cylindrical mould and tamping rod

be

strong enough to withstand crushing under roller and traffic. If the aggregate crushing value is 30 or higher’ the result may be anomalous and in such cases the ten percent fines value should be determined instead. REFERENCE STANDARDS: IS 2386-part4-1963 AIM: To determine the aggregate crushing value of coarse aggregates

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 98

INTERNSHIP REPORT

2018-2019

APPARATUS USED: 

Steel Cylinder Figure 45: Mould and specimen under UTM



Sieves (12.5mm,10mm)



Cylindrical metal measure



Tamping Rod



Balance (0-10kg)



Oven (1500c)



Compression testing Machine (2000KN)

PREPARATION OF SAMPLE Test sample consist of aggregate passing a 12.5mm IS sieve and retained on a 10mm IS sieve. The aggregate to be tested is dried in oven for a period of not less than 4 hours.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 99

INTERNSHIP REPORT

2018-2019

PROCEDURE  The cylindrical steel cup is filled with 3 equal layers of aggregate and each layer is tamped 25 strokes by the rounded end of tamping rod and the surplus aggregate struck off, using the tamping rod as a straight edge.  The net weight of aggregate in the cylindrical steel cup is determined to the nearest gram (WA) and this weight of aggregate is used for the duplicate test on the same material.  The cup is fixed firmly in position on the base of the machine and the whole of the test sample is added in thirds, each third being subjected to 25stokes from tamping rod.  The surface is leveled and the plunger is inserted so that it rests horizontally on the surface. The whole assembly is then placed between the platens of testing machine and loaded at a uniform rate so as to reach a load of 40 tones in 10 minutes.  The load is then released and all aggregate is removed from the cup and sieved on 2.36 mm. IS sieve until no further significant amount passes in one minute. The fraction passing the sieve is weighed to an accuracy of 0.1 g (WB) CALCULATION Weight of aggregates taken = 3 kg Aggregate crushing Value = (WB/WA) × 100 Trails

Sieve size

Passing weight in gm (P)

% of impact (P/T)

Trail 1

2.36mm

703

23.43

Trail 2

2.36mm

714

23.80

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 100

INTERNSHIP REPORT Avg. rate of impact =

2018-2019 = 23.61%

Types of Roads / Pavements

Aggregate Crushing Value Limit

Flexible Pavements Soling

50

Water bound macadam

40

Bituminous macadam

40

Bituminous surface dressing or thin premix carpet

30

Dense mix carpet

30

Rigid Pavements Other than wearing course

45

Surface or Wearing course

30

The table below shows limits of aggregate crushing value for different types of road construction: RESULTS: The aggregate impact value is 23.61 % CONCLUSION: The aggregates used in wearing surfaces should have the aggregate crushing value less than 30% And for buildings etc it should not more than 45%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 101

INTERNSHIP REPORT

2018-2019

7) LOS ANGELES ABRASION RESISTANCE DEFINITION:  The Los Angeles test is a measure of degradation of mineral aggregates of standard gradings resulting from a combination of actions including abrasion or attrition, impact, and grinding in a rotating steel drum containing a specified number of steel spheres.  Abrasion value is the percentage of aggregate weight that passing sieve (No. 12 = 1.7mm) after application of standard abrasion by mechanical rotation parallel with standard iron balls for a dry aggregate  The aggregate abrasion value shall not exceed the following values: a) For aggregates to be used in 30% concrete for wearing surfaces and b) For aggregates to be used in 50% other concrete IMPORTANCE:  The Los Angeles (L.A.) abrasion test is a common test method used to indicate aggregate toughness and abrasion characteristics.  Aggregate abrasion characteristics are important because the constituent aggregate in HMA must resist crushing, degradation and disintegration in order to produce a high quality HMA. Aggregate used in highway pavement should be hard and must resist wear due to the loading from compaction equipment, the polishing effect of traffic and the internal abrasion effect.

Figure 46: Test apparatus and Aggregate sample BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 102

INTERNSHIP REPORT

2018-2019

 The road aggregate should be hard enough to resist the abrasion of aggregate. Resistance to abrasion is determined in laboratory by loss angles abrasion test.  To choose the best type of aggregate due to abrasion value and to calculate the hardness of aggregates. Principle of the Test: To produce the abrasive action by use of standard steel balls which when mixed with the aggregate and rotated in a drum for specific number of revolution cause impact on aggregate. The %age wear due to rubbing with steel balls is determined and is known as abrasion value. Prepare the sample by the portion of an aggregate sample retained on the 1.70 mm (No. 12) sieve and place in a large rotating drum that contains a shelf plate attached to the outer wall.

Figure 47: Los Angeles Abrasion test machine REFERENCE STANDARDS: IS 2386-PART 4- 1963 AIM: Determination of abrasion value of coarse aggregates using los angeles machine. APPARATU USED:  Los Angeles machine - The Los Angeles abrasion testing machine shall consist of a hollow steel cylinder, closed at both ends, having an inside diameter of 700 mm and an inside length of 500 mm. The cylinder shall be mounted on stub shafts attached to the

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 103

INTERNSHIP REPORT

2018-2019

ends of the cylinders but not entering it, and shall mounted in such, a manner that it may be rotated about its axis in a horizontal position. An opening in the 37 cylinder shall be provided for the introduction of the test sample. A removable steel shelf, projecting radially 88 mm into the cylinder and extending its full length, shall be mounted along one element of the interior surface of the cylinder. The shelf shall be of such thickness and so mounted, by bolts or other approved means, as to be firm and rigid. The 1.70 mm IS Sieve  Balance.  Sieves of No. 12, 12.5 mm and 10mm  Iron or metallic balls (11) numbers, diameter is (4.8)mm and weight of each is (445)gm.  Oven. Abrasive Charge-The abrasive charge shall consist of cast iron spheres or steel spheres approximately 48 mm in. Diameter and each weigh% between 390 and 445 g. The abrasive charge, depending upon the grading of the sample as described above shall be as follows. GRADING

NUMBER OF SPHERES

WEIGHT OF CHARGE(g)

A

12

5000+/-25

B

11

4584+/-25

C

8

3330+/-20

D

6

2500+/-15

E

12

5000+/-25

F

12

5000+/-25

G

12

5000+/-25

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 104

INTERNSHIP REPORT

2018-2019

Test Sample The test sample shall consist of clean aggregate which has been dried in an oven at 105 to 110°C to substantially constant weight and shall conform to one of the gradings shown in Table II. The grading used shall be those most nearly representing the aggregate furnished for the work. TABLE II

GRADING OF TEST SAMPLE Sieve size (square hole) Weight in g of test sample for grade Passing in mm Retained in mm A B C D E F 80 63 2500* 63 50 2500* 50 40 5000* 5000* 40 25 1250 5000* 25 20 1250 20 12.5 1250 2500 12.5 10 1250 2500 10 6.3 2500 6.3 4.75 2500 4.75 2.36 5000 *Tolerance of ± 2% permitted

G 5000* 5000* -

PROCEDURE:



The test sample shall consist of clean aggregate which has been dried in an oven at

105 to 110°C to substantially constant weight and shall conform to one of the gradings shown in Table 3.22. The grading or gradings used shall be those most nearly representing the aggregate furnished for the work.



The test sample and the abrasive charge shall be placed in the Los Angeles abrasion

testing machine and the machine rotated at a speed of 20 to 33 rev/min. For gradings A, B, C and D, the machine shall be rotated for 500 revolutions; for gradings E, F and G, it shall be rotated for 1 000 revolutions.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 105

INTERNSHIP REPORT 

2018-2019

The machine shall be so driven and so counter-balanced as to maintain a

substantially uniform peripheral speed. If an angle is used as the shelf, the machine shall be rotated in such a direction that the charge is caught on the outside surface of the angle.



At the completion of the test, the material shall be discharged from the machine and

a preliminary separation of the sample made on a sieve coarser than the l.70 mm IS Sieve.



The material coarser than the 1.70 mm IS Sieve shall be washed dried in an oven at

105 to 110°C to a substantially constant weight, and accurately weighed to the nearest gram OBSERAVTIONS AND CALCULATIONS: LOS ANGELES ABRASION VALUE Sl. No.

Group

Sieve size in mm

Weight retained

Weight passing

% abrasion

in g

in g

index

1

A

1.70

4115

885

17.70

2

E

1.70

8576

1424

14.24

Percentage Los Angeles abrasion index = RESULTS: The Los Angeles abrasion resistance value for sample 1 = 17.70% The Los Angeles abrasion resistance value for sample 2 = 14.24% CONCLUSION: The Los Angeles abrasion resistance value shall not be more than 50% for Concrete and 30% for Wearing surfaces.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 106

INTERNSHIP REPORT

2018-2019

8) DETERMINATION OF 10% FINES VALUE DEIFINTION: Ten percent fines value is a measure of the resistance of aggregate crushing subjected to loading and it is applicable to both weak and strong aggregate. IMPORTANCE:  Granular sub-base is subjected to repeated loadings from truck types. The stress level at the contact points of aggregate particles is quite high. The sub-base in pavement is a structural layer used for distribution of traffic loads into larger area.  Ten percent fines value can be used to reveal the aggregate properties when subjected to mechanical degradation. AIM: For determination of the aggregates 10% fines value of coarse aggregate, which passes 12.5 mm. IS sieve and retained on 10 mm IS sieve REFERENCE STANDARDS: IS 2386 -Part IV -1963 APPARATUS USED: 

Steel cylinder



Sieves (12.5mm,10mm)



Cylindrical metal measure



Tamping Rod



Balance (0-10kg)



Oven (1500c)



Compression testing machine

PREPARATION SAMPLE

Figure 48: Aggregate sample under UTM

Test sample is dried in oven for a period of four hours at a temperature of 100 to 1100C.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 107

INTERNSHIP REPORT

2018-2019

PROCEDURE  The cylindrical measure is filled by the test sample of aggregate in three layers of approximately equal depth, each layer being tamped 25 times.  The test sample in the cylinder with the plunger in position is placed in the compression testing machine. The load is applied at a uniform rate so as to cause a total penetration of the plunger of about 20mm for normal crushed aggregates in 10 minutes.  For rounded or partially rounded aggregates, the load required to cause a total penetration of 15mm is applied where as for honeycombed aggregates a penetration of 24mm is applied in 10 minutes.  After the maximum specified load is reached, the load is released and the aggregate from the cylinder is sieved from 2.36mm IS sieve.  The fines passing 2.36mm.IS sieve is weighed and expressed as a percentage of by weight of the test sample. OBSERVATIONS AND CALCULATION: 10 % FINES VALUE Sl. No.

Sieve size in mm

Weight retained in g

Weight passing in g

% finer value

1

2.36

2615

340

11.33

RESULTS: Load required to crush the 10% of aggregate = X*14 Y+4

% Passing 2.36 mm sieve at X ton load Y = 11.33 The load for 20mm penetration of plunger X = 245 KN (for normal crushed aggregate) 10% Fines Value = 245*14 = 223.7 23 Tons 11.33+4

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 108

INTERNSHIP REPORT

2018-2019

3.C. FINE AGGREGATES DEFINITION: Those particles passing the 9.5 mm (3/8 in.) sieve, almost entirely passing the 4.75 mm (No. 4) sieve, and predominantly retained on the 75 µm (No. 200) sieve are called fine aggregate.

DIFFERENCE BETWEEN M-SAND AND RIVER SAND

Figure 49: M-sand and River sand sample Parameters

M Sand

Process

Manufactured in factory.

Naturally available on river banks.

Shape

Angular and has rougher texture. Angular aggregates demands more water. Water demand can be compensated with cement content.

Smoother texture with better shape. Demands less water.

Moisture Content

Moisture is available only in water washed M Sand.

Moisture is trapped in between the particles which is good for concrete purposes.

Concrete Strength

Higher concrete strength compared to river sand used for concreting.

Lesser concrete concrete compared to M Sand

Silt Content

Zero silt

Minimum permissible silt content is 3%. Anything more than 3% is harmful

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

River Sand

Page 109

INTERNSHIP REPORT

2018-2019 to the concrete durability. We can expect 5 - 20% slit content in medium quality river sand.

Over Sized Materials

0%. Since it is artificially manufactured.

1 - 6% of minimum over sized materials can be expected. Like pebble stones.

Marine Products

0%

1 - 2% like sea shells, tree barks etc

Eco Friendly

Though M Sand uses natural coarse aggregates to form, it causes less damage to environment as compared to river sand.

Harmful to environment. Eco imbalances, reduce ground water level and rivers water gets dried up.

Price

M Sand price ranges from Rs.35 - Rs.45 per cubic feet in Bangalore.

River sand price ranges from Rs 60 80 per cubic feet in Bangalore.

Applications

Highly recommended for RCC purposes and brick/ block works.

Recommended for RCC, plastering and brick/ block work.

Quality

Better quality control since manufactured in a controlled environment.

No control over quality since it is naturally occurring. Same river bed sand can have differences in silt contents.

Particle passing 75 micron

Up to 15% (IS: 383 - 1970)

Up to 3% (IS:383 - 1970)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 110

INTERNSHIP REPORT

2018-2019

LABORATORY TESTS ON FINE AGGREGATES a) SIEVE ANALYSIS b) SPECIFIC GRAVITY AND WATER ABSORPTION c) BULK DENSITY (LOOSE AND COMPACTED) d) SILT CONTENT

e)

MATERIAL FINER THAN 75 MICRON

ZONING OF FINE AGGREGATES: IS SIEVE

PERCENTAGE PASSING FOR ZONE I

ZONE II

ZONE III

ZONE IV

10mm

100

100

100

100

4.75mm

90-100

90-100

90-100

95-100

2.36mm

60-95

75-100

85-100

95-100

1.18mm

30-70

55-90

75-100

90-100

600 micron

15-34

35-59

60-79

80-100

300 micron

5-20

8-30

12-40

15-50

150 micron

0-10

0-10

0-10

0-15

0-20

0-20

0-20

0-20

River sand M-sand

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 111

INTERNSHIP REPORT

2018-2019

a) SIEVE ANALYSIS OF FINE AGGREGATES DEFINITION: Grading refers to the determination of the particle-size distribution for aggregate. Grading limits and maximum aggregate size are specified because grading and size affect the amount of aggregate used as well as cement and water requirements, workability, pumpability and durability of concrete.

Figure 50: Sieve sets IMPORTANCE:  If the water-cement ratio is chosen correctly, a wide range in grading can be used without a major effect on strength.  When gap-graded aggregate are specified, certain particle sizes of aggregate are omitted from the size continuum. Gap-graded aggregate are used to obtain uniform textures in exposed aggregate concrete.  Close control of mix proportions is necessary to avoid segregation. REFENCE STANDARDS: IS 2386-PART 1-1963 AIM: Determination of particle size distribution of Fine aggregates by sieve analysis APPARATUS USED:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 112

INTERNSHIP REPORT

2018-2019

μ

μ and pan

 IS Sieves set of size 10mm,4.75mm, 2.36mm, 1.18mm, 600μ, 300 , 150  Balance  Sieve shaker  Tray PROCEDURE:

 The sample shall be brought to an air dry condition. This may be achieved either by drying at room temperature or by heating at a temperature of 100 to 110°c. The air-dry sample shall be weighed and sieved successively on the appropriate sieves starting with the largest. Care shall be taken to ensure that the sieves are clean before use.  Each sieve shall be shaken separately over a clean tray for a period of not less than two minutes. The shaking shall be done with a varied motion, backward and forwards, left to right, circular clockwise and anti-clockwise, and with frequent jarring, so that the material is kept moving over the sieve surface in frequently changing directions.  On completion of sieving, the material retained on each sieve, together with any material cleaned from the mesh, shall be weighed.  The amount of aggregate placed on each sieve shall be such that the weight of the aggregate retained on the sieve at completion of the operation is not greater than the value given for that sieve in TABLE Below.

MAX. WT TO BE RETAINED AT THE COMPLETION OF SIEVING IS SIEVE 2.36mm 1.18mm 600 microns 300 microns 150 microns 75 microns

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

MAX. WT IN gm 200 100 75 50 40 25

Page 113

INTERNSHIP REPORT

2018-2019

M.SAND: WEIGHT= 500g SL NO.

1 2 3 4 5 6 7

SIEVE SIZE (mm) 10 4.75 2.36 1.18 0.600 0.300 0.150

WT. RETAINED (G) 0 0 48 117 59 130 77

% WT. RETAINED C 0 0 9.60 23.40 11.80 26.00 15.40

% PASSING (100 – C) 100 100 90.4 67.0 55.2 29.2 13.8

REMARKS

FALLS IN ZONE-2

Fineness modulus

=

= 2.47

RESULTS: The fineness modulus of fine aggregates is 2.47 and it comes under zone 2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 114

INTERNSHIP REPORT

2018-2019

b) SPECIFIC GRAVITY AND WATER ABSORPTION OF FINE AGGREGATES  Specific Gravity is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. It is the measure of strength or quality of the specific material. Aggregates having low specific gravity are generally weaker than those with higher specific gravity values.  Water Absorption is the ratio of weight of water absorbed to the weight of dry sample expressed as a percentage. It will not include the amount of water adhering to the surface of the particles.  SATURATED SURFACE DRY (S.S.D.) CONDITION is the condition related with the aggregate particles in which the permeable pores of the aggregate particles are filled with water but without free water on the surface of the particles.

Figure 51: pycnometer bottle and sample

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 115

INTERNSHIP REPORT

2018-2019

IMPORTANCE:  The main objective of these test is to measure the strength or quality of the material and to determine the water absorption of aggregates 

Aggregate specific gravity is used in a number of applications including Superpave mix design, deleterious particle identification and separation, and material property change identification.



Specific gravity of aggregates is require to be considered when we deal with light weight and heavy weight concrete.

 Specific gravities can vary widely depending upon aggregate type. Some lightweight shales can have specific gravities near 1.05, while other aggregate can have specific gravities above 3 The specific

Figure 52: Pycnometer bottle

gravity of sands is considered to be around 2.65. Aggregate absorption is a useful quality because:  High values can indicate non-durable aggregate.  Absorption can indicate the amount of asphalt binder the aggregate will absorb.  Water absorption of aggregates will affect the water – cement ratio and hence the workability of concrete REFERENCE STANDARDS: IS 2386- PART 3- 1963 AIM: determining the specific gravity, apparent specific gravity and water absorption of aggregates. APPARATUS:  Balance  Oven-A well ventilated oven, thermostatically controlled, to maintain a temperature of 100 to 110°C. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 116

INTERNSHIP REPORT

2018-2019

 Pycnometer of about 1 liter capacity having a metal conical screw top with a 6mm hole at its apex . The screw top shall be watertight .  Dry soft cloths Filter papers and funnel.  A means of supplying a current of warm air, such as a hair drier  A tray of area not less than 325 cm2.  An airtight container large enough to take the sample. PROCEDURE:  A sample of about 1 kg for 10 mm to 4-75 mm or 500 g if finer than 4.75 mm, shall be placed in the tray and covered with distilled water at a temperature of 22 to 32°C. Soon after immersion, air entrapped in or bubbles on the surface of the aggregate shall be removed by gentle agitation with a rod. The sample shall remain immersed for 24 ± 1/2 hours.  The water shall then be carefully drained from the sample, by decantation through a filter paper, any material retained being return& to the sample. The aggregate including any solid matter retained on the filter paper shall be exposed to a gentle current of warm air to evaporate surface moisture and shall be stirred at frequent intervals to ensure uniform drying until no free surface moisture can be seen and the material just attains a ‘freerunning’ condition. Care shall be taken to ensure that this stage is not passed. The saturated and surface-dry sample shall be weighed (weight A).  The aggregate shall then be placed in the pycnometer which shall be ‘filled with distilled water. Any trapped air shall be eliminated by rotating the pycnometer on its side, the hole in the apex of the cone being covered with a finger. The pycnometer shall be topped up with distilled water to remove any froth from the surface and so that the surface of the water in the hole is flat. The pycnometer shall be dried on the outside and weighed (weight B).  The contents of the pycnometer shall be emptied into the tray, care being taken to ensure that all the aggregate is transferred. The pycnometer shall be refilled with distilled water to the same level as before, dried on the outside and weighed (weight C). The difference in the temperature of the water in the pycnometer during the first and second weighing shall not exceed 2°C. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 117

INTERNSHIP REPORT

2018-2019

 The water shall then be carefully drained from the sample by decantation through a filter paper and any material retained returned to the sample. The sample shall be placed in the oven in the tray at a temperature of 100 to 110°C for 24 ± 1/2 hours, during which period it shall be stirred occasionally to facilitate drying. It shall be cooled in the air-tight container and weighed ( weight D ). OBSERVATIONS AND CALCULATIONS: OBSERVATIONS: A = weight of SSD sample = 520 gm B = Weight of sample + pycnometer + water = 1872 gm C = weight of pcnometer + water = 1554 gm D = weight of oven dried aggregates = 500gm CALCULATIONS:

= 2.48

=4% RESULTS: The water absorption of fine aggregate sample is 4 % and the specific gravity of fine aggregate sample is 2.48

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 118

INTERNSHIP REPORT c)

BULK

DENSITY

OF

2018-2019 FINE

AGGREGATES

(LOOSE

AND

COMPACTED) DEFINITION: Density is the weight of material in a given volume. IMPORTANCE:  If we know the bulk density of the aggregate material then we can easily determine the mass required to fill a unit volume container.  Bulk density also indicates the percentage of voids present in the aggregate material. This percentage of voids affects the grading of the aggregates which is important in high strength concrete.  Bulk density also indicates the compactive effort required to compact the concrete. REFERENCE STANDARDS: IS 2386- PART 3- 1963 AIM: Determination of bulk density of fine aggregates APPARATUS USED:  Balance  Cylindrical Metal Measure-The measure shall preferably be machined to accurate internal dimensions and shall be provided with handles. It shall also be watertight, and of sufficient rigidity to retain its form under rough usage, and should be protected against corrosion.  The measure shall be of 3j 15 or 30 litres capacity,, according to the maximum nominal size of the coarsest particles of aggregate and shall comply pith the requirements given in Table I.  Tamping Rod- A straight metal tamping rod of cylindrical cross section 16 mm in diameter and 60 cm long, rounded at one end

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 119

INTERNSHIP REPORT

2018-2019

SIZE OF CONTAINER FOR BULK DENSITY TEST: Size of largest

Nominal

particles

capacity

Inside diameter

Inside height

cm

cm

metal

Litre 4.75mm and

Min. thickness of

mm

3

15

17

3.15

15

25

30

4.0

30

35

31

5.0

under Over 4.75mm to 40 mm Over 40 mm .PROCEDURE:

 Condition of Specimen-The test shall normally be carried. out on dry material when determining the voids, but when bulking tests are required material with a given percentage of moisture may be used.  Rodded or Compacted Weight - The measure shall be filled about one-third full with thoroughly mixed aggregate and tamped with 25 strokes of the rounded end of the tamping rod. A further similar quantity of aggregate shall be added and a further tamping of 25 strokes given. The measure shall finally be filled to over-flowing, tamped 25 times and the surplus aggregate struck off, using the tamping rod as a straightedge. The net weight of the aggregate in the measure shall be determined and the bulk density calculated in kilograms per litre.

 Loose Weight - The measure shill be filled to overflowing by means of a shovel or scoop, the aggregate being discharged from a height not exceeding 5 cm above the top of the measure. Care shall be taken to prevent, as far as possible, segregation of the particle sizes of which the sample is composed. The surface of the aggregate shall then be levelled with a straightedge. The net weight of the aggregate in the measure shall then be determined and the bulk density calculated in kilogram per litre.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 120

INTERNSHIP REPORT Sl. No

2018-2019

Volume

of Size of sieve weight in kg

cylinder

in in mm

Bulk density in kg/litre (M/V)

litres

Loose bulk density

3

10 mm

4953

1651

Compacted bulk density

3

10mm

5700

1900

RESULTS: Bulk density of loose aggregates 1651 kg/m3 Bulk density of compaction aggregates 1900 kg/m3

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 121

INTERNSHIP REPORT

2018-2019

d) FREE SWELL INDEX (SILT CONTENT) OF FINE AGGREGATES DEFINITION: Free swell or differential free swell, also termed as free swell index, is the increase in volume of soil without any external constraint when subjected to submergence in water. Silt content is a fine material which is less than 150 micron. It is unstable in the presence of water. IMPORTANCE:  It is unstable in the presence of water. If we use silty sand for bonding, it will reduce the strength and cause rework. Excessive quantity of silt, not only reduces the bonding of cement and fine aggregates but also affects the strength and durability of work



AS PER IS:383-1970 THE SILT CONTENT SHOULD BE MAX 3% FOR UNCRUSHED SAND i.e, RIVER SAND AND MAX 15% FOR CRUSHED SAND i.e, CRUSHED STONE SAND.

REFERENCE STANDARDS: CPWD Code AIM: To Find out silt content in sand (fine aggregate) APPARATUS USED: 

250 ml measuring cylinder



Water



Sand & Tray

PROCEDURE:

Figure 53: Graduated cylinder



First, we have to fill the measuring cylinder with 1% solution of salt and water up to 50 ml.



Add sand to it until the level reaches 100 ml. Then fill the solution up to 150 ml level.



Cover the cylinder and shake it well (as shown in video)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 122

INTERNSHIP REPORT

2018-2019



After 3 hours, the silt content settled down over the sand layer



Now note down the silt layer alone volume as V1 ml (settled over the sand)



Then note down the sand volume (below the silt) as V2 ml



Repeat the procedure two more times to get the average

CALCULATIONS:

Figure 54: Test sample kept for settlement

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 123

INTERNSHIP REPORT Particulates

2018-2019 Distilled water

Initial volume

42

Final volume

46

Increase in volume

4

Free swell index

= 8.69% RESULT: The Silt content of a given soil sample =8.693 %

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 124

INTERNSHIP REPORT

2018-2019

3.D. BLOCKS HOLLOWS/SOLIDS

Figure 55: Solid concrete blocks Figure 56: Hollow concrete blocks

BLOCK — A concrete masonry unit, either hollow (open or closed cavity), or solid (other than units used for bonding, such as a half block), any one of the external dimension of which is greater than the corresponding dimension of a brick as specified in IS 3952, and of such size and mass as to permit it to be handled by one man. Further more, to avoid confusion with slabs and panels, the height of the block shall not exceed either its length or six times its width. THE NOMINAL DIMENSIONS OF CONCRETE BLOCK SHALL BE AS FOLLOWS:  Length: 400, 500 or 600 mm  Height: 200 or 100 mm  Width: 50,75, 100, 150,200, 2500r300 mm.

MATERIALS USED IN MANUFACUTRING PROCESS  Cement  Aggregates  Water  Admixtures

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 125

INTERNSHIP REPORT

2018-2019

TABLE2: PHYSICAL REQUIREMENTS

Type

Grade

Hollow (open and closed cavity) load bearing units

Solid load bearing unit

Density of block in kg/m2

A(3.5) A(4.5) A(5.5) A(7.0) A(8.5) A(10.0) A(12.5) A(15.0)

Not less than 1.5

Minimum average Compressive strength of units in N/mm2

Minimum Compressive strength of individual Units in N/mm2

3.5 4.5 5.5 7 8.5 10.0 12.5 15.0

2.8 3.6 4.4 5.6 7.0 8.0 10.0 12

B(3.5) B(5.0)

Less than 1.5 but more than 1.1

3.5 5.0

2.8 4.0

C(5.0) C(4.0)

Not less than 1.8

5.0 4.0

4.0 3.2

LABORATORY TESTS ON BLOCKS The laboratory tests conducted on hollow blocks or concrete blocks are:  Water absorption test  Compressive strength test  Block density test  Drying shrinkage  Moisture movement

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 126

INTERNSHIP REPORT

2018-2019

1) WATER ABSORPTION TEST OF CONCRETE BLOCKS DEFINITION: The increase in mass from dry condition to a soaked condition. IMPORTANCE:  Water absorption for blocks should not be greater than 10% by weight as per IS: 2185 (Part I) – 2005 (RA-2015)specifications.  Water absorption test is conducted to determine the durability property of the concrete block and also the quality of the block. REFERENCE STANDARDS: IS 2185 –PART1-1979 AIM: Determination of water absorption of concrete blocks SAMPLING:  At least three specimens shall be tested.  For control purposes the number of tests and sampling procedure shall confirm with the given control requirements. Whole blocks shall be used for testing.  The specimen is dried out, weighed and then submerged in a water bath for a period. Water absorption is the difference in mass between soaked and dry condition. APPARATUS USED:  Balance, allowing a reading to an accuracy of 0.1% of the specimens dry mass.  Ventilated oven, holding a temperature of 105 ± 2 º C  Water bath, holding a temperature of 23 ± 2 º C PROCEDURE:  The specimens shall be clean and free from mortar, otherwise no preparations are needed. BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 127

INTERNSHIP REPORT

2018-2019

 The dry mass (m) is measured after the test specimen has been dried to constant mass in the ventilated oven at a temperature of 105 ± 2 º C Constant mass is considered to be reached when the mass over a period of 2 h does not differ more than 0.1%.  After drying, the specimen is cooled and placed in the water bath. It shall be stored with half the specimen height submerged in water for 1 day, and completely under water for 2 days. Then the specimen is removed from the water, wiped with a damp cloth, and the wet mass m1 is measured within two minutes. CALCULATIONS: The water absorption of each test specimen is calculated by the formula:

Where m is the dry mass m1 is the wet mass determined by weighing in air after the specimen has been submerged in water for 3 days. SL NO. DRY WT. IN KG WET WT. IN KG WATER ABSORPTION % (W1)

(W2)

BY WT. INDIVIDUAL

1

32.320

33.510

3.68

2

32.090

33.630

4.80

3

33.190

34.580

4.19

AVG.%

4.22

RESULTS: The water absorption of given aggregates is 4.22%

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 128

INTERNSHIP REPORT

2018-2019

2) BLOCK DENSITY OF SOLID OR HOLLOW CONCRETE CUBES DEFINITION: It is the ratio of mass of the concrete block to the volume of the same block REFERENCE STANDARDS: IS 2185-PART 1-1979 AIM: To determine the block density of the given concrete hollow or solid blocks APPARATUS USED:

 Weighing balance  scale

Figure 57: Hollow concrete block

PROCEDURE: 3 blocks shall be taken to conduct this test. To determine the density of block, first heat the block in the oven to 100oc and then cooled it to room temperature. Now take the dimensions of block and from that find out the volume and weigh the block. The density of block is determined from the below relation and the average density of 3 blocks will be the final block density.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 129

INTERNSHIP REPORT

2018-2019

Density values of different grades of blocks should be as follows.

Type of unit

Hollow type unit

Solid type unit

Grade

Density of block (kg/m2)

A(3.5)

>/= 1500

A(4.5)

>/=1500

A(5.5)

>/=1500

A(7.0)

>/=1500

A(8.5)

>/=1500

A(10.0)

>/=1500

A(12.5)

>/=1500

A(15.0)

>/=1500

B(3.5)

1100-1500

B(5.0)

1100-1500

C(5.0)

>/=1800

C(4.0)

>/=1800

OBSERVATIONS: Mass of block = 32.32 kg Length of block = 400 mm Breadth of block = 200 mm Height of block = 200 mm Volume of blocks = 16000 cm3 Density of block =

= 2020 kg/m3

RESULTS: The block density of given block is 2020 kg/m3

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 130

INTERNSHIP REPORT

2018-2019

3) COMPRESSIVE STRENGTH TEST OF CONCRETE BLOCKS DEFINITION: Compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to tensile strength, which withstands loads tending to elongate. IMPORTANCE:  Concrete gains strength with time after casting. It takes much time for concrete to gain 100% strength and the time for same is still unknown. The rate of gain of concrete compressive strength in higher during the first 28 days of casting and then it slows down.  Strength is extremely important for any material and any construction project. You need to have the right amount of strength, in some cases no less and no more, to be able to accomplish the task.

Figure 58: Test specimen before, during and after test REFERENCE STANDARDS: IS 2185-PART 1-1979 AIM: Determination of compressive strength of concrete hollow or solid blocks.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 131

INTERNSHIP REPORT

2018-2019

APPARATUS: 1) TESTING MACHINE: The testing machine shall be equipped with two steel bearing blocks one of which is a spherically seated block that will transmit load to the upper surface of the masonry specimen, and the other a plane rigid block on which the specimen will rest. When the bearing area of the steel blocks is not sufficient to cover the bearing area of the masonry specimen, steel bearing plates meeting the requirements of (2) shall be placed between the bearing blocks and the capped specimen after the centroid of the masonry bearing surface has been aligned with the centre of thrust of the bearing blocks NOTE — It is desirable that the bearing faces of blocks and plates used for compression testing of concrete masonry have a hardened of not less than 60 (HRC). 2) STEEL BEARING BLOCKS AND PLATES The surfaces of the steel bearing blocks and plates shall not depart from a plane by more than 0.025 mm in any 15 mm dimension. The centre of the sphere of the spherically seated upper bearing block shall coincide with the centre of its bearing face. If a bearing plate is used, the centre of the sphere of the spherically seated bearing block shall lie on a line passing vertically through the centroid of the specimen bearing face. The spherically seated block shall be held closely in its seat, but shall be free to turn in any direction. The diameter of the face of the bearing blocks shall be at least 15 cm. When Steel plates are employed between the steel bearing blocks and masonry specimen the plates shall have a thickness equal to at least one-third of the distance from the edge of the bearing 7 block to the most distant corner of the specimen. In no case shall the plate thickness be less than 12 mm. TEST SPECIMENS:  Each full size units shall be tested within 72 h after delivery to the laboratory, during which time they shall be stored continuously in normal room air.  Units of unusual size, shape, or strength may be sawed into segments, some or all of which shall be tested individually in the same manner as prescribed for full size units.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 132

INTERNSHIP REPORT

2018-2019

The strength of the full size units shall be considered as that which is calculated from the average measured strength of the segments.  For the purpose of acceptance, age of the testing the specimens shall be 28 days. The age shall be reckoned from the time of the addition of water to the dry ingredients. CAPPING TEST SPECIMEN Bearing surfaces of the units shall be kept by one of the methods described in A and B. A) SULPHUR AND GRANULAR MATERIALS Proprietary or laboratory prepared mixtures of 40 to 60 percent sulphur (by mass), the remainder being ground fire clay or other suitable inert material passing 150-micron IS sieve with or without a plasticizer, shall be spread evenly on a non-absorbent surface that has been lightly coated with oil (see Note). The sulphur mixture shall be heated in a thermo statistically controlled heating pot to a temperature sufficient to maintain fluidity for a reasonable period of time after contact with the capping surface. Care shall be exercized to prevent overheating, and the liquid shall be stirred in the pot just before use. The capping surface shall be plane within 0.075 mm in 40 cm and shall be sufficiently rigid and so supported as not to be measurably deflected during the capping operation. Four 25 mm square steel bars shall be placed on the surface plate to form a rectangular mould approximately 12 mm greater in either inside dimension than the masonry units. The mould shall be filled to a depth of 6-mm with molten sulphur material. The surface of the units to be capped shall quickly be brought into contact with the liquid and the specimen held so that its axis is at right angles to the surface of the capping liquid, shall be inserted. The units shall be allowed to remain undisturbed until solidification is complete. The caps shall be allowed to cool for a minimum of 2 h before the specimens are tested. Patching of caps shall not be permitted. Imperfect caps shall be removed and be replaced with new ones. NOTE — The use of oil on capping plates may be omitted if it is found that plate and unit can be separated without damaging the cap. B) GYPSUM PLASTER CAPPING

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 133

INTERNSHIP REPORT

2018-2019

A neat paste of special high-strength plaster and water shall be spread evenly on a non-absorbent surface that has been lightly coated with oil. Such gypsum plaster, when gauged with water at the capping consistency shall have a compressive strength at a 2 h age of not less than 25 N/mm 2, when tested on 50 mm cubes. The casting surface plate shall conform to the requirements described in ‘A’. The surface of the unit to be capped shall be brought into contact with the. capping paste; the specimen which is held with its axis at right angles to the capping surface, shall be firmly pressed down with a single motion. The average thickness of the cap shall be not more than 3 mm. patching of caps shall not be permitted, imperfect caps shall be removed and replaced with new ones. The caps shall be aged for at least 2 h before the specimens are tested. PROCEDURE:  Positioning of Specimens: Specimens shall be tested with the centroid of their bearing surfaces aligned vertically with the centre of thrust of the spherically seated block of the testing machine. Except for special units intended for use with their cores in a horizontal direction, all hollow concrete masonry units shall be tested with their cores in a vertical direction. -Masonry units that are hundred percent solid and special hollow units intended for use with their hollow cores in a horizontal direction may be tested in the same direction as in service.  NOTE — for homogeneous materials, the centroid of the bearing surface shall be considered to be vertically above the centre of gravity of the masonry units.  Speed of Testing The load up to one-half of the expected maximum load may be applied at any convenient rate, after which the control of the machine shall be adjusted as required to give a uniform rate of travel of the moving head such that the remaining load is applied in not less than one nor more than two minutes. CALCULATION AND REPORT  The compressive strength of a concrete masonry unit shall be taken as the maximum load, in Newtons, divided by the gross cross-sectional area of the unit, in square milIimetres. The gross area of a unit is the total area of a section perpendicular to the

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 134

INTERNSHIP REPORT

2018-2019

direction of the load, including areas within cells and within re-entrant spaces unless these spaces are to be occupied in the masonry by portions of adjacent masonry.  Report be results to the nearest 0.1 N/mm2 separately for each unit and is the average for the 8 unit

Dimensions of block SL. NO

Contact area mm2

Load in kN (P)

LxBxH

Compressive strength in N/mm2

1

402x200x198

79596

500

6.28

2

400x200x199

79600

470

5.90

3

400x200x200

80000

550

6.88

4

400x100x200

40000

170

4.25

Average compressive strength =

= 5.82N/mm2

RESULTS: The compressive strength of given blocks is 5.82 N/mm2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 135

INTERNSHIP REPORT

2018-2019 3.E. BRICKS

DEFINITION: A brick is building material used to make walls, pavements and other elements in masonry construction.

CLASSIFICATION BASED ON METHOD OF MANUFACTURING Bricks can broadly be categorized into two types as follows on the basis of how its manufactured: 1. Unburnt or sun-dried bricks 2. Burnt bricks

UNBURNT BRICKS: Unburnt bricks or sun-dried bricks are the types which are dried with the help of heat received from sun after the process of moulding. These bricks can only be used in the construction of temporary and cheap structures. Such bricks should not be used at places exposed to heavy rains.

BURNT BRICKS Burnt bricks are prepared by burning the brick-mould in the kiln inside the factory. These are the most commonly used bricks for construction works. They can be further classified into following four categories: 1.

FIRST CLASS BRICKS These bricks are table-moulded and of standard shape and they are burnt in kilns. The surfaces and edges of the bricks are sharp, square, smooth and straight. They comply with all the qualities of good bricks. These bricks are used for superior work of permanent nature.

2.

SECOND CLASS BRICK These bricks are ground-moulded and they are burnt in kilns. The surface of these bricks is somewhat rough and shape is also slightly irregular. These bricks may have hair cracks and their edges may not be sharp and uniform. These bricks are commonly used at places where brickwork is to be provided with a coat of plaster.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 136

INTERNSHIP REPORT 3.

2018-2019

THIRD CLASS BRICKS These bricks are ground-moulded and they are moulded in kilns. These bricks are not hard and they have rough surfaces with irregular and distorted edges. These bricks give dull sound when struck together. They are used for unimportant and temporary structures and at places where rainfall is not heavy.

4.

FOURTH CLASS BRICKS These are over-burnt type of brick with irregular shape and dark colour. These bricks are used as aggregate for concrete in foundations, floors, roads, etc. because of the fact that the over-burnt bricks have a compact structure and hence they are sometimes found to be stronger than even the first class bricks.

ADVANTAGES OF BRICKS  Aesthetic: Bricks offer natural and a variety of colors, including various textures.  Strength: Bricks offer excellent high compressive strength.  Porosity: The ability to release and absorb moisture is one of the most important and useful properties of bricks, regulating temperatures and humidity inside structures.  Fire Protection: When prepared properly a brick structure can give a fire protection maximum rating of 6 hours.  Sound Attenuation: The brick sound insulation is normally 45 decibels for a 4.5 inches brick thickness and 50 decibels for a nine-inch thick brick.  Insulation: Bricks can exhibit above normal thermal insulation when compared to other building materials. Bricks can help regulate and maintain constant interior temperatures of a structure due to their ability to absorb and slowly release heat. This way bricks can produce significant energy savings, more than 30 percent of energy saving when compared to wood.  Wear Resistant: A brick is so strong, that its composition provides excellent wear resistance.  Efflorescence: Efflorescence forms on concrete structures and surfaces when soluble salts dissolved in water are deposited and accumulated on surfaces forming a visible scum.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 137

INTERNSHIP REPORT

2018-2019

 Durability: Brick is extremely durable and perhaps is the most durable man-made structural building material so far.

DISADVANTAGES OF BRICKS 

Time consuming construction



Cannot be used in high seismic zones



Since bricks absorb water easily, therefore, it causes fluorescence when not exposed to air



Very Less tensile strength



Rough surfaces of bricks may cause mold growth if not properly cleaned



Cleaning brick surfaces is a hard job



Color of low quality brick changes when exposed to sun for a long period of time

LABORATORY TESTS ON BRICKS Following tests are conducted on bricks to determine its suitability for construction work. 1. Absorption test 2. Crushing strength test 3. Hardness test 4. Shape and size 5. Color test 6. Soundness test 7. Structure of brick 8. Presence of soluble salts (Efflorescence Test)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 138

INTERNSHIP REPORT

2018-2019

1) WATER ABSORPTION TEST ON BRICKS DEFINITION: The water absorption is the increase in mass from dry condition to a soaked condition. IMPORTANCE:  Water absorption test on bricks are conducted to determine durability property of bricks such as degree of burning, quality and behavior of bricks in weathering.  A brick with water absorption of less than 7% provides better resistance to damage by freezing.  The degree of compactness of bricks can be obtained by water absorption test, as water is absorbed by pores in bricks.  The water absorption by bricks increase with increase in pores. So, the bricks, which have water absorption less than 3 percent can be called as vitrified.

Figure 59: Water absorption of bricks

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 139

INTERNSHIP REPORT 

2018-2019

This test provides the percentage of water absorption of bricks and procedure of the same is discussed below.

REFERENCE STANDARDS: IS 1077-1992 (Reaffirmed 2011) APPARATUS USED:  Balance, allowing a reading to an accuracy of 0.1% of the specimens dry mass.  Ventilated oven, holding a temperature of 105 ± 2 º C  Water bath, holding a temperature of 23 ± 2 º C  SPECIMEN: Three numbers of whole bricks from samples collected for testing should be taken PROCEDURE:  Dry the specimen in a ventilated oven at a temperature of 105 °C to 115°C till it attains substantially constant mass.  Cool the specimen to room temperature and obtain its weight (M1) specimen too warm to touch shall not be used for this purpose.  Immerse completely dried specimen in clean water at a temperature of 27+2°C for 24 hours.  Remove the specimen and wipe out any traces of water with damp cloth and weigh the specimen after it has been removed from water (M2). OBSERVATIONS AND CALCULATION: Dimensions of the specimen: 210 X 100 X 75 mm Weight of dry bricks: Specimen 1: W1 = 2346g Specimen 2: M1 = 2350g BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 140

INTERNSHIP REPORT

2018-2019

Weight of water absorbed bricks: Specimen 1: W2 = 2700g Specimen 2:M2 = 2720g Weight of water absorption = W2-W1 Specimen 1: 354g Specimen 2: 370g Percentage of water absorption =

*100

Specimen 1: W = 15.08 % Specimen 2: M = 15.74% WAvg =

15.41 %

Water absorption, % by mass, after 24 hours immersion in cold water in given by the formula, The average of result shall be reported. RESULT: Water absorption of the given bricks = 15.41% Water Absorption Values for Bricks: When tested as above, the average water absorption shall not be more than 20% by weight up to class 12.5 and 15% by weight for higher class.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 141

INTERNSHIP REPORT

2018-2019

2) COMPRESSIVE STRENGTH OF BRICKS DEFINITION: Compressive strength test on bricks are carried out to determine the load carrying capacity of bricks under compression. This test is carried out with the help of compression testing machine. IMPORTANCE:  Bricks are generally used for construction of load bearing masonry walls, columns and footings. These load bearing masonry structures experiences mostly the compressive loads. Thus, it is important to know the compressive strength of bricks to check for its suitability for construction  The bricks, when tested in accordance with the procedure laid down in IS 3495 (Part I ) : 1992 shall have a minimum average compressive strength for various classes as given in below table.  The compressive strength of any individual brick tested shall not fall below the minimum compressive strength specified for the corresponding class of brick. The lot shall be then checked for next lower class of brick.

Figure 60: Bricks under UTM

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 142

INTERNSHIP REPORT

2018-2019

CLASSES OF COMMON BURNT CLAY BRICKS :

Avg. Compressive strength not less than Class designation

N/mm2

Kgf/cm+

35

35

350

30

30

300

25

25

250

20

20

200

17.5

17.5

175

15

15

150

12.5

12.5

125

10

10

100

7.5

7.5

75

5

5

50

3.5

3.5

35

AIM: For determination of compressive strength of bricks REFERENCE STANDARD: IS 3495 – P (1)-1992 APPARATUS USED: 

Compression Testing Machine



Scale for measuring dimension of brick



Water bath



Cement mortar

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 143

INTERNSHIP REPORT

2018-2019

PROCEDURE  Unevenness observed in the bed faces of bricks is removed to provide two smooth and parallel faces by grinding. It is immersed in water at room temperature for 24 h.  The specimen is then removed and any surplus moisture is drained out at room temperature. The frog and all voids in the bed face are filled with cement mortar (1 cement, clean coarse sand of grade 3 mm and down). It is stored under the damp jute bags for 24 h followed by immersion in clean water for 3 days.  The specimen is placed with flat faces horizontal, and mortar filled face facing upwards between two 3 ply plywood sheets each of 3 mm thickness and carefully centered between plates of testing machine.  Load is applied axially at a uniform rate of 14 N/mm 2 per minute till failure occurs. The maximum load at failure is noted down. The load at failure is considered the maximum load at which the specimen fails to produce any further increase in the indicator reading on the testing machine. OBSERVATIONS AND CALCULATION: Mortar cover = to be filled on frog Total height of brick = 70 mm Area of specimen = 18900 mm2 Formulae used:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 144

INTERNSHIP REPORT

2018-2019

Crushing Specimen no.

Dimension

Load

Compressive strength

(P kN ) (P/A) 1

210 X 100 X 75 mm

144

6.85

2

210 X 100 X 74 mm

130

6.19

RESULTS: 5 numbers of bricks should be tested and the average value is reported.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 145

INTERNSHIP REPORT

2018-2019

4.0. REINFORCED STEEL DEINITION: Reinforced steel is a steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension.  Concrete is strong under compression, but has weak tensile strength. Rebar significantly increases the tensile strength of the structure. Rebar's surface is often deformed to promote a better bond with the concrete.  The most common type of rebar is carbon steel, typically consisting of hot-rolled round bars with deformation patterns. Other readily available types include stainless steel, and composite bars made of glass fiber, carbon fiber, or basalt fiber

THE CONTENTS OF REINFORCEMENT STEEL Constituents

Percent, maximum

Fe415

Fe415D

Fe415SS

Fe500

Fe500D

Fe500S

Fe550

Fe550D

Fe600

Carbon

0.30

0.25

0.25

0.30

0.25

0.25

0.30

0.25

0.30

Sulphur

0.060

0.045

0.045

0.055

0.040

0.040

0.055

0.040

0.040

Phosphorus

0.060

0.045

0.045

0.055

0.040

0.040

0.050

0.040

0.040

Sulphur and phosphorus

0.110

0.085

0.085

0.105

0.075

0.075

0.100

0.075

0.075

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 146

INTERNSHIP REPORT

2018-2019

THE NOMINAL SIZE OF BARS:  Nominal size, 4 mm, 5 mm, 6 mm, 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 28 mm, 32 mm, 36 mm, 40 mm, 45 mm, 50 mm

THE NOMINAL CROSS-SECTIONAL AREA AND MASS:

Nominal size in mm

cross sectional area in mm2

mass per metre in kg

4

12.6

0.099

5

19.6

0.154

6

28.3

0.222

8

50.3

0.395

10

78.6

0.617

12

113.1

0.888

16

201.2

1.58

20

314.3

2.47

25

491.1

3.85

28

615.8

4.83

32

804.6

6.31

36

1018.3

7.99

40

1257.2

9.86

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 147

INTERNSHIP REPORT

2018-2019

TERMINOLOGY For the purpose of this standard, the following definitions shall apply. 1. BATCH— Any quantity of bars/wires of same size and grade whether in coils or bundles presented for examination and test at one time. 2. BUNDLE— Two or more coils or a number of lengths properly bound together. 3. ELONGATION— The increase in length of a tensile test piece under stress. The elongation at fracture is conventionally expressed as a percentage of the original gauge length of a standard test piece. 4. LONGITUDINAL RIB— A uniform continuous protrusion, parallel to the axis of the bar/wire (before cold-working, if any) 5. NOMINAL DIAMETER OR SIZE— The diameter of a plain round bar/wire having the same mass per meter length as the deformed bar/wire. 6. NOMINAL MASS— The mass of the bar/wire of nominal diameter and of density 0.00785 kg/mm2 per meter. 7. NOMINAL PERIMETER OF A DEFORMED BAR/WIRE = 3.14 times the nominal diameter.

8. PERCENT PROOF STRESS— The stress at which a non-proportional elongation equal to 0.2 percent of the original gauge length takes place.

9. PERCENTAGE TOTAL ELONGATION AT MAXIMUM FORCE— The elongation corresponding to the maximum load reached in a tensile test (also termed as uniform elongation).

10. TENSILE STRENGTH— The maximum load reached in a tensile test divided by the effective cross-sectional area of the gauge length portion of the test piece (also termed as ultimate tensile stress).

11. TRANSVERSE RIB— Any rib on the surface of a bar/wire other than a longitudinal rib.

12. YIELD STRESS— Stress (that is, load per unit cross sectional area) at which elongation first occurs in the test piece without increasing the load during the tensile test. In the case of steels with no such definite yield point, proof stress shall be applicable

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 148

INTERNSHIP REPORT

2018-2019

ADVANTAGES OF USING STEEL REINFORCEMENT BARS: 

Modulus of Elasticity: Steel has high modulus of Elasticity i.e. 200GPa (200 x 10⁹ N/m²). This helps the steel to stretch in tension(upto 200GPa) without breaking and regain its shape on removal of load.



Ductility of Steel: Ductility of steel is high. i.e. Steel rebar will behave ductile under higher loads.



Ductility is the ability of material to allow plastic deformations (i.e. permanent change in its dimensions) under application of load before breaking.



Coefficient of Thermal Expansion: Steel and concrete has almost same coefficient of thermal expansion (change in dimension due to temperatures). Due to this both (concrete and steel) will experience same length changes in high temperatures.



Resistance: Steel is resistant to rough conditions during transport, storage, bundling and placing on construction site. If minor damage happens, it does not significantly affect its performance.



Strength: It is strong enough to withstand high impact load.



Readily Available: Structural Steel industry has enough production capacity to meet the demands of construction industry and is available at ease for any house construction.



Ready Build: These days ready build steel is also available. Ready build steel eliminate the time of cutting and bending. This saves lots of construction time as well as minimizes the wastage of steel in bending and cutting.



Steel can be recycled easily.

DISADVANTAGES OF USING STEEL REBAR: 

High Cost: Steel is expensive and considerably increases the cost of structure.



High Temperatures: Steel show tendency to melt in extremely high temperatures. This is also one of the reasons; steel is tied and not welded.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 149

INTERNSHIP REPORT 

2018-2019

Reaction: Too little concrete cover allows the water to penetrate and react with steel rebars causing concrete to crack. Occasionally concrete aggregates react with steel causing concrete to spall.



Rust: Steel exposed to weather rusts and reduces the strength of reinforced concrete. When rusts start building up around the steel rebars, it causes severe internal pressure on the surrounding concrete, leading to cracks in concrete.



Weight: It is a light weight material.

TESTS ON REBARS: 1.

Tensile test

2.

Bend and Rebend test

1) TENSILE TEST ON REBARS DEFINITION: The test involves straining a test piece by tensile force, generally to fracture, for the purpose of determining tensile strength, yield strength, event ductility and reduction of area.  GAUGE LENGTH (L) - length of cylindrical or prismatic portion of the test piece on which elongation is measured at any moment during the test [m].  ORIGINAL GAUGE LENGTH (L0) - gauge length before application of force [m].  FINAL GAUGE LENGTH (LU) - gauge length after rupture of the test piece [m].  ELONGATION - increase in the original gauge length at the end of the test.  DUCTILITY – percentage elongation after fracture (A) - permanent elongation of the gauge length after fracture, expressed as the percentage of the original length.

 EXTENSION – increase of the original length at a given moment of the test  PERCENTAGE REDUCTION OF AREA (Z) - maximum change of cross sectional area, which was occurred during the test, expressed as a percentage of the original crosssectional area.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 150

INTERNSHIP REPORT

2018-2019

 MAXIMUM FORCE (FM) - the greatest force which the test piece withstand during the test [N].  STRESS (Σ) - force at any moment during the test divided by the original cross-sectional area (S0) of the test piece

 TENSILE STRENGTH (RM) - stress, corresponding to the maximum force Fm.

 YIELD STRENGTH (RY) – when metallic material exhibits a yield phenomenon, a point is reached during the test at which plastic deformation occurs without any increase in the force.

 PROOF STRENGTH (Rp) - stress at which extension is equal to a specified percentage of the gauge length. the symbol used is followed by a suffix giving the prescribed percentage for example Rp.0.2 REFERENCE STNDARDS: IS 1786-2008 AIM: This method shall be used to determine the yield point, ultimate strength, and percent elongation. APPARATUS USED:  Rebars of required dia  U.T.M  Scale  Marker or chock piece Test Pieces

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 151

INTERNSHIP REPORT

2018-2019

The shape and dimensions of the test pieces depend on the shape and dimensions of the metallic products the mechanical propertbartait leies of which are to be determined. The test piece is usually obtained by machining a sample from the product. However product of constant cross-section may be subjected to test without being machined. The cross section of the test pieces may be circular, square, rectangular, annular or, in special cases, of some other shape. Determination of Original Cross-Section Area The original cross-section area S0 shall be calculated from measurements of the dimensions of the test piece.  For products of circular cross-section and smooth surface S0 may be calculated from formula:

S0 =

[mm2 ]

Where d is the arithmetic mean of two measurements carried out in two perpendicular direction  For products of ribbed surface S0 may be determined from the mass of a known length L and its density (7850 kg/m3) according the formula :

[m²] Determination of Original Gauge Length: Elongation is not equal through the whole length of the test piece. At the point of fracture is biggest and decreases with the distance from this point. This is the reason, why the percentage elongation after fracture is determined on special length – original gauge length. Test pieces could be proportional and non-proportional.  Proportional test pieces have the original gauge length in relation with the original cross-section area according the formula

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 152

INTERNSHIP REPORT

2018-2019

L0= k* Where k is equal to 5,65 ( eventually 11,3 ) S0 original cross-sectional area * In the case of test pieces with the circular cross-section this formula gives: Lo = 5 d (For k = 11,3 Lo = 10 d ) Where d is diameter of the test piece  Non-proportional test pieces may be used if specified by the product standard. Test pieces of circular cross-section shall preferably have the dimensions given in Tabular column K

5.65

Diameter d in Original C/s area S0 in Original

gauge Total length Lt in mm

mm

mm2

length L0 in mm

20±0.150

314.2

100±1.0

10±0.075

78.5

50±0.5

5±0.04

19.6

25±0.25

Depends on the method of fixing the test piece in the machine grips Lt > Lc + 2d

Determination of Final Gauge Length Standard EN 1002 – 1 says that measurement of final gauge length is valid only if the distance between the fracture and the nearest gauge mark is not less than one third of the original gauge length. In order to avoid having to reject test pieces in which fracture may occur outside the limits, the method based on sub-division of L0 into N equal parts may be used: Before the test sub-divide the original gauge length into N equal parts. Recommended value of N is 10 and the size of one part is than L0/10. Make the complementary scale (scale division is equal to one part) along the total test piece.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 153

INTERNSHIP REPORT

2018-2019

After fracture the two broken pieces of the test piece are carefully fitted back together so that their axes lie in a straight line. Special precaution shall be taken to ensure proper contact between the broken parts. From the point of fracture measure five parts on each side (together 10 parts) and it is final gauge length Lu. If there is not enough parts (less than five) at one side, than final gauge length is determined in this way (see Fig.:37): on the shorter piece measure the distance from the fracture to the last mark. This distance is La on the longer piece measure the distance from fracture to the mark, corresponding to five parts Lb on the longer piece find the parts, symmetrically (from fracture) corresponding to the parts, which miss on the shorter part. This distance is Lc final gauge length is than equal to : Lu = La + Lb + Lc Lc

Lb

La

Lc

Lu PROCEDURE:  Before testing measure diameter of the test piece, determine cross-sectional area S0 and original gauge length L0. Complementary scale shall be marked along the whole test piece. The marks could not result in premature fracture.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 154

INTERNSHIP REPORT

2018-2019

 Grip the test piece in the jaws of the test machine. Ensure that test pieces are held in such a way that the force is applied as axially as possible.  Prepare writing device for making of stress-strain diagram  Apply load by prescribed rate of stressing. Within the elastic range the rate of stressing shall be within the limits given in Tab below. Within the plastic range the straining rate shall not exceed 0.0025/s for determination of yield strength and 0.008/s for determination of tensile strength.  After fracture put down the maximum force Fm, measure the final gauge length Lu and minimum diameter after fracture. From stress-strain diagram find the force at the point of yield Fy  Determine tensile strength Rm, yield strength Ry, percentage elongation after fracture A, minimum cross-sectional area and percentage reduction of the area Z according chap. RATE OF STRESSING Modulus of elasticity of material

Rate of stressing

N/mm2

N/mm2/s

< 150

2

10

≥150

6

30

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 155

INTERNSHIP REPORT

2018-2019

Figure 61: Rebar under UTM and measuring of elongation of bar

Identification

Diameter

Weight

Length

Yield

Ultimate

Initial

Final

Elongation

of bars in

in kg

in cm

stress in

load in

length

length in

length in %

kN (0.2%

kN

in cm

cm

mm

PL) TMT steel

12

0.821

112.2

51.5

58.5

6

7.5

25.0

India gold

16

1.559

111.6

112.5

128.5

8

9.8

22.5

Fe-500

20

2.440

100.2

187.5

215.0

10

11.7

17.0

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 156

INTERNSHIP REPORT

2018-2019

RESULTS: 1) Area = Area of 12mm dia bar = 113.112 mm2 Area of 16mm dia bar = 201.088mm2 Area of 20mm dia bar = 314.2mm2 2) yield stress = Yield stress of 12mm dia bar = 455.30 N/ mm2 Yield stress of 16mm dia bar = 559.45 N/ mm2 Yield stress of 20mm dia bar = 596.75 N/ mm2 3) ultimate tensile stress = Ultimate tensile stress of 12mm dia bar = 517.18 N/ mm2 Ultimate tensile stress of 16mm dia bar = 639.02 N/ mm2 Ultimate tensile stress of 20mm dia bar = 684.27 N/ mm2 4) guage length = 5.65 But length = 1 m Guage length of 12mm dia bar =60.09mm Guage length of 16mm dia bar = 80.12 mm Guage length of 20mm dia bar = 100.15 mm

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 157

INTERNSHIP REPORT

2018-2019

2) BEND AND REBEND TEST DEFINITION:  BEND TEST: The bend test consists of submitting a test piece of round, square, rectangular, or polygonal cross section to plastic deformation by bending, without changing the direction of loading, until a specified angle of bend is reached. This bend test is conducted for determining the ability of metallic materials to undergo plastic deformation in bending.  REBEND TEST: Concrete reinforcing steel bars are generally produced in strands 6 to 12 meter in length so that bending for transportation and handling purposes becomes necessary. At the site bars are straightened, and then sometimes re-bent for assembling purposes. This process will result in a loading and re-loading of steel. Thus, bend and/or re-bend test is necessary to gain information about the ductility of the steel bar. IMPORTANCE:  The severity of the bend test is primarily a function of the angle of bend and inside diameter to which the specimen is bent, and of the cross-section of the specimen. These conditions are varied according to location and orientation of the test specimen and the

Figure 62: Bend test sample under UTM and sample after test

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 158

INTERNSHIP REPORT

2018-2019

chemical composition, tensile properties, hardness, type, and quality of the steel specified.  The purpose of re-bend test is to measure the effect of strain ageing on steel. Strain ageing has embrittlement effect which takes place after cold deformation by diffusion of nitrogen in steel. Hence, there is limitation stated in some design codes to restrict the nitrogen content of steel to 0.012%.

Figure 63: Rebend test sample under UTM REFERENCE STANDARDS: IS 1599-1985 APPARATUS USED: The bend test shall be carried out in testing machines or presses equipped with the following devices:  Bending device with two supports and a mandrel: The length of the supports and the width of the mandrel shall be greater than the width or diameter of the test piece. The diameter of the mandrel is determined by the material standard. The test piece supports shall be rounded to a radius between 1 and 10 times the thickness of the test piece and shall be sufficiently hard. *

Unless otherwise specified, the distance between the supports, I shall be taken as approximately:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 159

INTERNSHIP REPORT 1=D+3a

2018-2019 and shall not change during the bend test.

 Bending device with a V-block and a mandrel: The tapered surfaces of the V-block shall form an angle of 180” - α *

The edges of the V-block shall be rounded to a radius between 1 and 10 times the thickness of the test piece and shall be sufficiently hard.  Bending device with a clamp: The device consists of a clamp and a mandrel of sufficient hardness; it may be equipped with a lever for applying force to the test piece.

Figure 64: Simple bend, Bend by use of V-block and Angle bend over a specified Radius PROCEDURE:  In general, the test is carried out at ambient temperature between 10 and 35%. Tests carried out under controlled conditions shall be made at a temperature of 23 f 5°C.  The bend test is carried out using one of the following methods specified in the relevant standard:  That a specified angle of bend is achieved under the force and for the given conditions

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 160

INTERNSHIP REPORT

2018-2019

 That the legs of the test piece are parallel to each other at a specified distance apart while under the force  That the legs of the piece are in direct contact while under the force  In the bend test to a specified angle of bend, lay the test piece on the supports or on the V-block and bend it in the middle between the supports by the action of a continuously increasing force.  Apply the bending force slowly so as to permit free plastic flow of the material  If it is not possible to bend the test piece to the specified angle , complete the bend by pressing directly on the ends of the legs of the test piece.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 161

INTERNSHIP REPORT

2018-2019 5.0. TILES

DEFINITION:

A tile is

a

manufactured

piece

of

hard-wearing

material

such

as ceramic, stone, metal, or even glass, generally used for covering roofs, floors, walls, showers, or other objects such as tabletops. Alternatively, tile can sometimes refer to similar units made from lightweight materials such as perlite, wood, and mineral wool, typically used for wall and ceiling applications

Figure 65: Tiles

PROPERTIES OF GOOD TILES: General properties  It should be of a regular shape and size.  It should be free from twists, cracks or flaws.  It should be well burnt and have uniform colour.  It should give a clear ringing sound when struck.  It should be sound and hard.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 162

INTERNSHIP REPORT

2018-2019

 Its broken surface should show an even and compact structure. FOLLOWING ARE SOME IMPORTANT PROPERTIES OF CERAMIC TILES:  Durability: Ceramic tile is more durable as compared to other types of tiles that are used as floor and wall tiles.  Strength: It has a high strength at high temperature.  Dirt Resistance: Ceramic tiles do not retain dust or residues as easily as many another flooring It can be cleaned with common household materials.  Colour Permanence: Ceramic tile that is exposed to sunlight will not lose their colour or began to fade. Due to this property, it helps to ensure that it will remain in original condition for their entire lifetime.  Slip Resistance: Unglazed ceramic tiles have greater slip resistance than glazed ceramic tiles and are recommended for areas subjected to high water spillage. Many glazed and unglazed ceramic tiles also feature an abrasive grit on their surface, increasing their slip resistance significantly. These tiles are best suited to public areas with direct access to the outdoors. Ceramic tiles for bathroom are more popular as it is more slip resistant.  Fire Resistance: Ceramic tiles are completely fireproof at any temperature. The surface will not alter, nor will it give off any toxic gases, smoke or fumes during a fire. Also, tile has also been found to protect structural surfaces during fires.  Heat Resistance: It has low electrical conductivity, low thermal conductivity, low and poor thermal expansion.  Hygiene: The surface of ceramic tiles will not retain liquids; absorb fumes, odours or smoke. They are also easy to clean and this helps in achieving good hygiene. This tile is suited for any environment where hygiene is necessary, i.e. ceramic tiles for bathroom.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 163

INTERNSHIP REPORT

2018-2019

 Chemical Resistance: Ceramic tiles are highly resistant to chemical agents. It has better resistance to alkalise and acids.  Stain Resistance: The stain resistance of ceramic tiles depends on its capacity to absorb moisture. It has a low resistance to stain. Glazed ceramic tiles are stain resistant. Ceramic tile stain is difficult to remove if the oil drops on the floor.  Water Absorption: It is very porous and hence absorbs water easily. So the tiles may get damaged quickly.  Frost Resistance: These types of tiles have less frost resistance because it absorbs water easily.

TEST ON TILES FLEXURAL STRENGTH TEST REFERENCE STANDARDS: IS: 13630 (Part-6) AIM: Determination of modulus of rupture and breaking strength of a whole tile by means of three point loading, the central point being in contact with the glazed surface of the tile. APPARATUS USED:  Drying oven having capacity of 110±50C  Recording gauge – Accurate to 2%  Two support cylindrical rods – These rods are made up of metal and the part of the rod which will be in contact with the test specimen must be covered with rubber having required hardness. One of theses two rods should be slightly pivotable and the other one should be slightly rotatable about its own axis. The dimension of the rods and the thickness of the rubber covering the metal rod should be as per table-1.  Central cylindrical rod – The construction of this rod is same as that of support rod and it should be slightly pivotable. The dimension of the rods and the thickness of the rubber covering the metal rod should be as per table-1.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 164

INTERNSHIP REPORT

2018-2019

Table – 1 Diameter of Rods, Thickness of Rubber and Length

Dimension of Tile (mm)

Diameter of Rod (d), in mm

Thickness of Rubber (t), in mm

Overlap of Tile Beyond the edge supports (l), in mm

≥ 95

20

5

10

< 95 ≥ 48

10

2.5

5

< 48 ≥ 18

5

1

2

section across modulus ofrupture apparatus Table-2 Dimension of Tile (mm)

 Minimum number of Test Specimen

≥ 48

 7

< 48 ≥ 18

 10

PROCEDURE FOR SAMPLE PREPARATION  Each sample consists of 7 or 10 no’s of test specimens depending upon their dimension. (see the table-2)  Preferable whole tile should be tested to find the accurate test result. But if the length of any tile is more than 300 mm or if it is non rectangular in shape, then cut it, so that it fits in the testing machine.  Dry the cut specimens in the oven maintained at a temperature of 110±5 0C until it attains constant mass.

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 165

INTERNSHIP REPORT

2018-2019

TEST PROCEDURE  Place a test specimen on two support rods with the glazed surface facing upward. It should be placed in such a way so that the specimen projects by the length ‘l’ (as given in tbla-1) beyond each support rod.  Note: For extruded tiles, place the tiles so that the projecting ribs are at right angles to the support rods. For all other rectangular tiles the greater side is at right angle to the support rods.  Position the central rod on the glazed surface of the test specimen and make sure that it is equidistance between the two support rods.  Note: If the tile has relief surfaces, then place a 2 nd layer of rubber of appropriate thickness (as given in table-1), on the central rod.  Apply the load evenly in such a way as to obtain a rate of increase of stress of 1±2 N/mm 2/s.  Record the load (F) when the specimen breaks.  Continue the steps 1 to 4 for all the test specimens in a sample.

Figure 66: Flexural test machine and sectional view

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 166

INTERNSHIP REPORT

2018-2019

OBSERVATIONS AND CALCULATIONS: Thickness

average

Dry

Wet weight

Load in

Thickness along

weight in

in kg

kN

broken edge

Average

kg 10/10.1/10.3/10.2

10.15

8.276

8.390

14.699

9.6/9.3/9.5/9.7

9.32

10.5/10.2/10/10

10.175

8.295

8.305

17.533

10/10/10.5/9.5

10.0

8.3/8.1/8.4/8.62

8.355

6.650

6.686

10.327

8/8.2/8/8

8.05

Lever arm constant (LAC)

12

12

12

breaking load in kg (p)

10.327

8.812

10.924

Span b/w supports (L)

280

280

280

Tile width in mm (B)

200

200

200

Tile thickness in mm(T)

8.05

7.47

7.97

Flexural strength

39.40

39.04

42.51

Flexural strength Where, P = Load required to break the tile, in N L = Centre to centre length between two support rods, in mm b = Width of the tile, in mm t = Minimum thickness of the test specimen measured after the test along the broken edge, in mm Flexural strength

= 39.40 N/mm2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 167

INTERNSHIP REPORT Flexural strength Flexural strength Average Flexural strength =

2018-2019 = 39.04 N/mm2 = 42.51 N/mm2 = 40.31 N/mm2

RESULTS: The average flexural strength of tile is 40.31 N/mm2

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 168

INTERNSHIP REPORT

2018-2019 6.0. REFERENCE

SOIL: 1. Moisture content by oven dried method – IS 2720-(PART2)-1973 2. Sieve Analysis - IS 2720-(PART4)-1985 3. Specific Gravity - IS2720-(PART3)-1980 4. Atterberg limits - IS 2720 (Part 5) 1985 5. Compaction test - IS 2720 PART 7-1980 6. Direct shear test - IS: 2720-Part 13-1986 7. Free swell index - IS 2720-PART 40-1970 8. CBR - IS 2720(Part 16)-1973 “Soil mechanics and foundation – 16th edition” b Dr. B.C. Punmia

CONCRETE CUBES: 1. Compressive strength - IS 516-1959

CEMENT: 1. Normal consistency of cement - IS4031-PART 4- 1988 2. Setting time of cement - IS 4031- PART 5-1988 3. Compressive strength - IS 4031- PART 6- 1988

COARSE AGGREGATE:

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 169

INTERNSHIP REPORT

2018-2019

1. Sieve Analysis - IS:2386-(Part I)-1963 (Reaffirmed 2016) 2. Bulk Density (Loose & Rodded) - IS:2386-(Part III)-1963 (Reaffirmed 2016) 3. Flakiness Index & Elongation - IS:2386-(Part I)-1963 (Reaffirmed 2016) 4. Water Absorption - IS:2386-(Part III)-1963 (Reaffirmed 2016) 5. Aggregate Impact Value - IS:2386-(Part IV)-1963 (Reaffirmed 2016) 6. Los Angeles Abrasion Resistance - IS:2386-(Part IV)-1963 (Reaffirmed 2016) 7. Aggregate Crushing Value - IS:2386-(Part IV)-1963 (Reaffirmed 2016) 8. Determination Of 10% Fines Value - IS:2386-(Part IV)-1963 (Reaffirmed 2016)

FINE AGGREGATE: 1. Sieve Analysis - IS:383-2016 2. Specific Gravity - IS:2386-(Part III)-1963 (Reaffirmed 2016) 3. Bulk Density (Loose & Rodded) - IS:2386-(Part III)-1963 (Reaffirmed 2016) 4. Silt content - IS 2720 (Part XL) – 1977

BLOCKS HOLLOW / SOLID: 1. Water Absorption - IS:2185-(Part I)-1979 (Reaffirmed 2016)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 170

INTERNSHIP REPORT

2018-2019

2. Compressive Strength - IS:2185-(Part I)-1979 (Reaffirmed 2016) 3. Block Density - IS:2185-(Part I)-1979 (Reaffirmed 2016)

BRICKS: 1. Water Absorption - IS:1077-1992 (Reaffirmed 2011) 2. Compressive Strength - IS:3495-(Part I to IV)-1992 (Reaffirmed 2011)

REINFORCED STEEL: 1. Tensile test - IS 1786-2008 2. Bend rebend test - IS 1599-1985

TILES: 1. Flexural strength - IS: 13630 (Part-6)

BE DEPT. OF CIVIL ENGINEERING –AGMRCET, VARUR

Page 171