Assignment On Construction Quality Management

ASSIGNMENT Course Title

- Construction Quality Management

Quality: Dr.Joseph M Juran has defined quality as ‘’fitness for use’’.Quality is viewed as one that requires every member of the organization to provide the next person in the process with an acceptable product or service. This means that everyone is responsible to perform a task in such a manner that the product can be used immediately and in the most efficient manner possible. As per ISO 9000 quality is the totality of feature and characteristics a product or service that bears on its ability to safely stated or implied needs. There is an urgent need for observance of quality in all aspects of construction via quality of materials, quality of workmanship and proper balance in the quality attained vis a vis the quality desired. STANDARDS AND SPECIFICATIONS FOR MAKING AND TRANSPORTING CONCRETE The quality of construction depends upon right materials used, the correct methods followed and produce end product of acceptable performance. The means of quality control are tests, inspection, supervision and analysis of data etc. Quality tests are conducted in laboratories and inspection & supervision are carried out on the site and the data analysis is done by experts in office. SPECIFICATIONS The project authorities prepare the process of working out specifications of various facilities where concrete will be used. However, the standards and specifications for concrete and its various ingredients are universally standardized and they are required to be in conformity with same. Indian Standards IS for concrete and its basic ingredients viz cement, coarse and fine aggregates, water admixtures and various aspects of concreting its placement and final acceptance should be as per IS specifications. The quality control of concrete comprises of the following four functions: i.

Control of ingredients of concrete viz. cement, coarse and fine aggregates, water and admixtures.

ii.

Concrete mix proportioning of concrete mix design to attain the required strength specifications.

iii.

Concrete production and placement operations.

iv.

Acceptance The responsibility of all the four functions is shared by contractor, the department or client and the quality control staff. INSPECTION

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Inspection is the act of physical verification of the subject work on the site and under normal day to day working conditions. The inspection for quality is done by quality control inspectors who are posted at all active sites and who should be persons at deputy engineer and above levels. They are member of the quality control team and unrelated to the production process directly. Once quality standards and other things are laid out inspection becomes a routine matter. Inspection stages are as follow: i.

Material inspection at supplier’s end

ii.

Material inspection at the stage of receipt

iii.

Material inspection at the stage of issue

iv.

Inspection of the process at the time of initial setting of machine / equipment

v.

Inspection of the trial run batch

vi.

Inspection while the execution is in progress

vii.

Inspection of finished process

viii.

Inspection before erection and commissioning

ix.

Inspection of commissioning

x.

Inspection of machinery and equipment commissioned

CHECKLIST Following items must be checked by Quality control engineer. 1. PRELIMINARY i.

Plans and specifications availability at sites

ii.

Organization chart, job descriptions and work assignments

iii.

Permissible tolerance of measurements

iv.

Provisions of records and reports

v.

Contractor’s plant, calibrations, equipment organisation and methods.

2. PROPORTIONING i.

Tests of aggregates

ii.

Proportioning of mix

iii.

Mix computations

iv.

Grading of mixed aggregates, batch quantities , yield

v.

Air content Page 2

3. MATERIALS i.

General ( applies to all materials)

ii.

Identification, quantities ( used on hand ) ,acceptability, uniformity, storage conditions, handling methods, waste, schedule of testing

iii.

Cement

iv.

Sampling for laboratory test

v.

Protection from dampness

vi.

Aggregates

vii.

Acceptability tests

viii.

Gradation , organic matter, deleterious substances,soundness,resistance to abrasion, other tests

ix.

Control test

x.

Moisture, absorption , specific gravity, unit weight, voids

undesirable

4. STOCKPILING i.

Water

ii.

Admixture

iii.

Reinforcing steel

iv.

Size, bending, surface condition

v.

Accessories

vi.

Fixtures

vii.

Other materials

5. BEFORE CONCRETING i.

Lines and grades

ii.

Excavation, foundations location , dimensions, shape, drainage, preparation for surfaces

6. FORMWORK i.

Specified type of forms

ii.

Location

iii.

Alignment , provision for settlement

iv.

Stability ( bearing ,shores, ties and spaces)

v.

Inspection of openings Page 3

vi.

Preparation of surfaces

vii.

Final clean up

7. GANGWAY AND LADDERS i.

Working platforms , location width, guardrails

ii.

Scaffoldings of adequate strength securely supported, properly braced

iii.

Suitable guards on all gangway and stairs

iv.

Ladders securely fixed

8. PLANT AND MACHINERY i.

Availability of spare concrete mixers,vibrators and other machines

ii.

Adequate electric and petromax lamps for concreting at night

iii.

Adequate quantity of tarpaulin to cover concrete in case of rains

9. BATCHING AND MIXING OF CONCRETE i.

For each batch, check the quantity of coarse aggregate, fine aggregate , cement and water, quantity of water being corrected from the viewpoints of dry wet conditions of the coarse and the fine aggregate

ii.

Periodical checking of accuracy, serviceable conditions and cleanliness of all the measuring equipments

iii.

Checking that water / cement ratio is maintained at the stipulated value. Further control over the amount of water used shall be exercised in terms of slump/compaction factor value

iv.

Physical checking of the quantities of the constituents per batch periodically

v.

Checking of workability of concrete at frequent intervals

vi.

Checking cleanliness of the mixer machine drum

vii.

Checking the working of the mixer as per the rating of the mixer ,yielding concrete of uniform colour and consistency

viii.

Checking cleanliness and adequacy of chairs in the area of concreting

ix.

Checking that concrete is placed and compacted before the expiry of initial setting time of cement and left undisturbed afterwards

x.

Checking that concrete is placed in even layers, each layer being compacted before placing the next layer

xi.

Ensuring that concreting is carried out continuously up to the construction joint

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xii.

Ensuring that while concreting an old work, the surface is chipped, cleaned with wire brush and wetted with a coat of cement slurry, before laying new concrete

10.EMBEDDED PARTS i.

Inspection of embedded parts and embedment of lugs

ii.

Position and level of embedded parts

iii.

Precautionary measures to keep the embedded parts in position

iv.

Position , depth and size of bolt holes

11.REINFORCEMENT IN PLACE i.

Size (diameter,lenghth,bends and anchorage)

ii.

Location ( number of bars, minimum clear spacing,mimimum cover)

iii.

Splicing

iv.

Stability ( binding by wire, chairs and spacers)

v.

Cleanliness ( no loose rust, no oil, paint dried mortar etc)

vi.

Fixtures ( location, stability, cleanliness)

vii.

Opening not shown on plans

viii.

Calibration of batching devices

ix.

Conditions of mixer, speed of operation

x.

Provision for continuous placement

xi.

Provision for curing

xii.

Provision for protection against sun,rain,hot or cold weather

xiii.

Adequate tools and men for compaction, finishing and curing

12.CONCRETING i.

Working conditions Weather, preparations completed, specified interval placement, lighting for night work, covering and protection

ii.

since

previous

Batching Cement, aggregates, water, admixtures Check batching devices Check yield of concrete

iii.

Mixing Page 5

Minimum time, batches delayed in mixer, maximum time, loading, number of revolutions of drum, water used, mixing capacity of drum, amount of concrete iv.

Control of consistency a. Observations of concrete being placed,tests,adjustments of water or admixtures in mix b. Monitoring of air content c. Concrete temperature check d. Conveying e. No segregation of materials, no excessive stiffening or drying out, time limits

v.

Placing uniform and dense concrete Continuous operation, preparation of contact surfaces, mortar bedding, vertical drop, no dropping against forms or reinforcement, little or no flow after depositing, depth of layers, water gain, rock pockets, removal of temporary ties and spacers, disposal of rejected batches, placing concrete under water

vi.

Contraction joints a. Location b. Forming or tooling c. Dowels of ties (if any ) in place and aligned

vii.

Construction and hinge joints a. Location, preparation of surfaces b. Dowels or ties (if any) in place and aligned c. Expansion and isolation joints d. Joint filler material,location,alignment,stability,freedom interference with subsequent movement

from

viii.

Finishing of formed surfaces shallow surfaces, layer of mortar, water gain, no over working first floating, alignment of surface, final hard trowelling, plastic shrinkage cracks

ix.

Finishing of formed surfaces condition of surfaces upon removal of forms (honeycomb peeling, ragged tie holes, ragged from lines), repair of defects, surface treatment, no surface drying

x.

Schedule of testing

13.AFTER CONCRETING Page 6

i.

Protection from damage impact, overloading of surfaces

ii.

Time of removal of forms

iii.

Curing surface continuously moist, time of beginning curing, length of curing period, concreting in cold and hot weather required precautions

iv.

Joints clean and seal

v.

Tests of concrete

vi.

Records and reports a. Records,materials,mix computations, batching and mixing, placing and curing b. Reports, daily, summary c. Diary d. Photographs, video recording

QUALITY ASSURANCE Quality assurance refers to the managerial process which determine the organisation’s design, objectives and resources, the project team, funding agencies, performance standards and feedback on the project’s performance, appropriate actions to deal with deviations and all steps necessary for promoting quality awareness at all levels and in all parts of the project organisation. A typical quality assurance programme addresses itself to the following: i.

Organisation structure of the project team and quality assurance department

ii.

Responsibilities and powers of the various personnel involved

iii.

Identification of the coordinating personnel

iv.

Quality and its programmes

v.

Quality education and awareness

vi.

Quality circles

vii.

Training

viii.

Setting up of MIS for quality

ix.

Resolution of technical differences and disputes

x.

Preparation of quality assurance manuals and their checklists

xi.

Vendor survey procedure

xii.

Vendor surveillance procedure

QUALITY ASSURANCE ORGANISATION/ UNIT AT SITE Page 7

At construction site generally a Quality control engineer is responsible for the quality assurance and quality control. He has mainly four functions as follow: i.

Setting up of standards and specifications

ii.

Evaluating materials, processes and outputs through appropriate tests, inspection etc

iii.

Appraising failures to these standard and acting when standards are not being adhered to

iv.

Planning improvements in the standards and specifications.

Quality control engineer’s functions include the following: i.

Development of specifications

ii.

Interaction with project designers

iii.

Reliability and development testing

iv.

Process capability studies

v.

QC of incoming materials

vi.

Vendor QC and vendor development

vii.

Quality planning for control of construction process

viii.

Inspection and testing during construction

ix.

Interaction with services engineering

x.

Records and procedures -

QC record accumulation procedure

-

Document control procedure

-

In built drawing control procedure

-

Non conformance control procedure

BIBLIOGRAPHY / REFERENCE 1. Construction Quality Management, Published by NICMAR ,2008 2. Total Quality Management by Parag Diwan,Published by Golden Books Centre Sdn.Bhd.Kuala lampur,1999

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