Maintenance Of Roads

Maintenance of Roads The objective should be to keep the road surface and appurtenances in good condition, and to extend the life of the road asset to the maximum extent possible. The activities include identification of defects and the possible causes thereof, determination of appropriate remedial measures, implementation of these in the field and monitoring of the results. This will involve identification, evaluation, planning, scheduling, management of men, materials and equipments, reporting and performance evaluation.

Basic Maintenance Objectives (a) Comfort, convenience and safety are afforded to the public (b) The investment in roads, bridges and appurtenances is preserved (c) The aesthetics and compatibility of highway system with the environment is preserved, and (d) The necessary expenditure of resources is accomplished with continuing emphasis on economy.

Classification of Maintenance activities 1. Ordinary repairs/ routine maintenance: (i) Upkeep of road pavements and side shoulders (ii) Upkeep of roadside drain system (iii) Upkeep of culverts and bridges, and earth retaining structures and parapets (iv) Keeping the sign boards, KM stones and other traffic aids and furniture in good shape and condition (v) Maintenance of roadside arboriculture; and (vi) Upkeep and maintenance of rest houses, inspection bungalows and gang huts. 2. Periodic maintenance: It covers periodic renewals to the carriageway whether it is graveled road, medaled road or black topped road to ensure the adequate level of serviceability is maintained. 3. Special repairs and flood damage repairs: This include the details of urgent repairs not covered under ordinary repairs/ periodic maintenance.

Planning of Maintenance Activities I Inventory of road: The following data are required to have a complete inventory: (a) District map on the scale of 1 : 50,000 (b) Strip maps of particular section of the road (c) Surface history of the road II Condition survey: (a) By visual inspection, and (b) By mechanical evaluation

Suggested minimum frequency of inspection for condition survey

Type of road

N.H./ S.H.

E.E. Routine

D.E.E. Special

Routine

Once in two months Twice a Before (Jan, year (April and after March, & monsoons May, July, October) Sept., Nov. & Dec.

Section I/C Special

Routine Special

Before and after Once a monsoons month Twice during rains

Every week

Check list of items required to be inspected during Inspection for maintenance of roads (a)Safety aspects: (i) Safety precautions for blockade and breaches taken (ii) Deep cuts on roads (iii) Damaged culvert/ bridge (iv) Branches of trees at less height (v) Power line crossings provided with guard cradles as per IRC:32 (vi) Vertical clearances for power lines should be as per IRC:32 (vii) Horizontal clearances for poles carrying power and telecommunication lines as per IRC:32 (viii) Berms not lower than 25mm for carriageway, and (ix) For new plantation only, the horizontal clearances to be kept as minimum 5m wherever possible

(b) Carriageway and crust conditions: (i) Location magnitude of potholes and patches, (ii) Condition of edges, (iii) Magnitude and location of undulations, and (iv) Location of crust failure, along with their causes (c) Berms (Shoulders): (i) Width of berms is adequate or not as per PWD specifications (ii) Cross slope kept as 3 to 5 percent (iii) Side slopes (iv) Berms properly dressed, and (v) If turning exists, whether it is properly cut or not

(d) Road drainage: (i) Cross-sectional area of drains adequate or not (ii) To check if the drains are blocked or damaged, and (iii) Whether proper disposal is provided to the drains (e) Road fixture: (i) KM stone, 5th KM stone, 200m stone and boundary stones exists in proper condition (ii) Traffic signs correctly located and maintained (iii) Location and condition of berms on curves and high embankments (iv) Painting and number of culverts required, and (v) History of the road mentioned on KM stones (f) Road protection works: (i) Retaining walls and pitchings on slopes properly maintained or not (ii) Condition of drains, spouts and weep holes in retaining walls and in pitchings on slopes, and (iii) Condition of parapet walls on culverts, etc.,

(g) Roadside Trees: (i) Check in numbering of trees done or not (ii) Disposal of dead trees, and (iii) Register of trees maintained. (h) Road Geometrics: (i) Horizontal curves laid out properly or not (ii) Extra width on curves conforms to IRC:38 (iii) Sight distances conform to IRC standards (iv) Vertical curves properly laid out or not, and (v) Ruling gradients conform to IRC standards

Field procedure for inspection and planning maintenance works: Each road should be divided in sections of 5 km and each Km should be further sub-divided into 200m stretches for inspection purposes. The extent of defects should be marked in bar lines extending over lengths which they occur and the severity of the defect may be marked in colours as detailed below: Severe: Less severe: Defect: Ordinary:

Requiring urgent action in red Requiring special attention in dotted red Requiring recurrent action in blue in dotted blue

Methods of assessment (i) Visual assessments: (ii) Side drains and turn outs: Side drains should be maintained at least one meter below the formation level. (iii) Corrugations: (iv) Rutting: (v) Potholes: The area covering majority of potholes should be measured along with number in every 200metreage (vi) Camber and Cross-fall (vii) Loss of materials: The thickness of the WBM layer should be checked at 15m intervals to assess the loss of material. (viii) Cracking:

Maintenance criteria Feature

Criteria Action Features concerned with safety of traffic:

Priority

Major breaches in the roadway

Any type of breach which endangers safety of traffic and causes obstruction to flow of traffic

Urgent

Minor cuts, ruts or blockades

Cuts or blockades which do not Get blockades completely obstruct the traffic removed and get but endanger safety of traffic the cuts repaired

Urgent

Branches of trees at height less than 4.5m over the roadway

Any kind

Get them cut in order of lower ones first

Special attention

Feature

Criteria

Action

Priority

Carriageway and crust conditions:

Cracking not accompanied by rutting

Cracking in local areas equal to or less than 25% of the total area

Local sealing or filling of the cracks with slurry seal or fog seal

Routine

Cracking in large areas exceeding 25% of the total area

Surface dripping

Special attention

In local areas not exceeding 25% of the total area

Apply local sealing

Routine

In long areas exceeding 25% of the total area

Apply surface dressing, use antistripping compounds

Special attention

Stripping

Feature

Bleeding

Rutting

Criteria

Action

Priority

in local areas not exceeding 25% of the total area

Spread and roll over 6mm size aggregate, heated to 600c

Routine

Apply surface dressing

Special attention

in local areas exceeding 25% of the total area

Apply tack coat @ 0.50 kg/sq.m and fill bituminous mix using a Less than 50mm rake and leaving an excess accompanied by thickness of about one third the Routine cracking depth of rut. Compact till surface is levelled and local sealing of cracks More than 50mm accompanied by cracking

With surface dressing over cracks, overlay required

Work of original nature

Feature

Criteria

Action

Priority

Potholes

Potholes, as soon as they occur

Local restoration by patching preferable

Special attention

Widely spaced cracks

Slurry for fog seal

Recurrent

Closely spaced cracks

Apply surface dressing

Special attention

Any extent

Patch road edge and repair shoulder

Recurrent

Defective camber

Any extent

Check and correct by reconstructioning to proper camber profile

Special attention

Undulations

Any extent

Investigate the cause and rectify

Special attention

Loss of material from unpaved road

Any extent

Do re-gravelling

Special attention

Reflection cracks Edge subsidence and rutting

Maintenance criteria for Shoulders and Side drains Feature Deformation or scour of shoulders Silting of side drains Damage or scouring of drain

Criteria

Action

Priority

Any extent

Fill and compact and bring its surface to desired camber

Routine

Any extent

Clean out the drains

routine

Any extent

Reconstruct to adequate shape and size

Special attention

Maintenance criteria for C.D. works : causeways

Feature

Criteria

Action

Priority

Potholes in paved surface

Any extent

Repair by filling

Special attention

Erosion at inlet/ outlet

Any extent

repair

Special attention

Any

Repair/ replace

Special attention

Guide posts/ flood gauge missing

Maintenance criteria for C.D. works : culverts

Feature

Criteria

Silting

Any

Erosion at inlet/ outlet

Any extent

Settlement cracks

Any

Action

Priority

Desilting

Special attention

repairs

Special attention

Repairs

Special attention

Maintenance criteria for Other works Feature

Criteria

Action

Priority

Road furniture and warning signs dirty or corroded or damaged or missing

Any extent

Clean and repair/ replace

routine

Fix new one

Special attention

Missing road signs

any

Criteria for renewal Renewal cycle of bituminous surfacing depends on traffic density, rainfall and lane width.

Type of renewal and periodicity of the renewal treatment for

Class of road

N.H.

Lane width

Single

Low Traffic rainfall (comme up to rcial) 150 cm per year Less than 450

SD 4

Medium rainfall 150 – 300 cm per year

High rainfall above 300 cm per year

SD 4

SD 4

N.H.

N.H.

Single

Double

450 to 1500

SD 4

SD 3

SD 3

More than 1500

PC 6

PC 5

PC 4

MS 8

MS 7

MS 6

Less than 450

SD 5

SD 4

SD 4

450 to 1500

SD 4

SD 3

SD 3

More than 1500

PC 6

PC 5

PC 4

MS 8

MS 7

MS 6

SD - Single coat of surface dressing with 0.10 cum of chips and 11 kgs of bitumen for 10 sqm. PC - 20mm premix chipping carpet as per Ministry’s specification MS - Mix Seal Surfacing as per Ministry’s specifications

Symptoms, causes and treatment of defects in Bituminous Surfacing: Surface defects Type of distress

Symptoms

Collection of Fatty binder on surface the surface

Probable causes

Possible type of treatment

Excessive binder in premix, spray or tack coat, loss of aggregates; excessively heavy axle loads

Sand blinding; open graded premix; liquid seal coat; burning of excess binder; removal of affected area

Type of distress

Symptoms

Probable causes

Possible type of treatment

Smooth surface

Slippery

Polishing of aggregates under traffic; excessive binder

Resurfacing with surface dressing or premix carpet

Streaking

Presence of alternate lean and heavy lines of bitumen

Non-uniform application of bitumen or at a low temperature

Application of a new surface

Insufficient Short and fine The treatment will bitumen, Hairline cracks at close depend on whether excessive filler intervals on the cracks or improper pavement is structurally surface sound or unsound. compaction Where the pavement is structurally sound, the Weak cracks should be filled pavement, with a low viscosity unstable binder or a slurry seal Interconnected conditions of or fog seal depending Alligator cracks forming a subgrade or upon the width of cracks series of small lower layers, cracks. Unsound blocks excessive over cracked pavements will loads or need strengthening or brittleness of rehabilitation treatment binder

Longitudinal cracks

Edge cracks

Poor drainage The treatment will shoulder depend on whether settlement, weak pavement is structurally Crack on a joint between sound or unsound. straight line adjoining spreads Where the pavement is along the road of pavement structurally sound, the layers or cracks should be filled differential frost with a low viscosity heave binder or a slurry seal or fog seal depending upon the width of Lack of support from shoulder, cracks. Unsound Crack near and poor drainage, cracked pavements will parallel to frost heave, or need strengthening or pavement edge inadequate rehabilitation treatment pavement width

Cracks in The treatment will transverse depend on whether Shrinkage of pavement is structurally direction or Shrinkage bituminous interconnected sound or unsound. cracks cracks forming a layer with age Where the pavement is series of large structurally sound, the blocks cracks should be filled with a low viscosity binder or a slurry seal or fog seal depending upon the width of Sympethetic Due to joints cracks. Unsound cracks over and cracks in Reflection joints and cracks the pavement cracked pavements will cracks need strengthening or in the pavement layer underneath underneath rehabilitation treatment

Symptoms, causes and treatment of defects in Bituminous Surfacing: Deformation Formation of crescent shaped cracks Slippage pointing in the direction of the thrust of wheels

Rutting

Removal of the Usual thrust of wheel in a surface layer in direction, lack or failure of the affected bond between surface area and and lower pavement replacement courses with fresh material

Heavy channelised traffic Longitudinal inadequate compaction of depressional in pavement layers, poor the wheel stability of pavement tracks material or heavy bullock cart traffic

Filling the depressions with premix material

Formation Corrugations of regular undulations

Shoving

Localised bulging of pavement surface along the crescent shaped cracks

Scarification Lack of stability in mix, and relaying of oscillations set up by surfacings, of vehicles, springs or cutting of high faulty laying of surface spots and filling course of low spots

Unstable mix, lack of Removing the bond between layers, or material to firm stop type movements base and and those involving relaying a negotiation of curves stable mix and gradients

Shallow depressions

Settlement and upheaval

Localised shallow depressions

Presence of inadequately compacted pockets

Large deformation of pavement

Where fill is weaks, the defective fill should be Poor compaction of excavated and refills, poor drainage, done. Where inadequate inadequate pavement or frost pavement is the heave cause, the pavement should be strengthened

Filling with premix material

Spreading and compacting heated Use of hydrophilic sand over the Separation of aggregate, inadequate affected area in the bitumen mix composition, Disintegrcase of surface from continuous contact ation: dressing; aggregate in with water, poor bond Stripping replacement with the presence between binder and fresh bituminous of moisture aggregate, poor mix with added compaction etc., anti-stripping agent in other cases

Loss of aggregate

Ageing and hardening Rough of binder, striping poor Application of liquid surface with bond between binder seal, fog seal or loss of and aggregate slurry seal aggregate in insufficient binder, depending on the some brittleness of binder extent of damage portions etc.,

Raveling

Failure of binder Poor compaction, poor bond between binder Application of cutback to hold the and aggregate or covered with coarse aggregate shown insufficient binder, sand, or slurry seal or up by pock marks brittleness of binder, a premix renewal coat or eroded areas on the surface etc.,

Ingress of water into Appearance of the pavement, lack of bowl-shaped bond between the Potholes holes, usually after surfacing and WBM rain base, insufficient bitumen content, etc.,

Edge breaking

Irregular breaker of pavement edges

Filling potholes with premix material or penetration patching

Cutting the affected area to regular Water infiltration poor sections and relateral support from building with shoulders, inadequate simultaneous attention strength of pavement paid to the proper edges, etc., construction of shoulders