Maintenance of Roads
Content
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 retainin structures and parapets (iv) Keeping the sign boards, KM stones and other traffic ai 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 repair 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 frequency of inspection for condition survey
Type of road
N.H./ S.H.
E.E. Routine
Special
D.E.E. Routine
Special
Section I/C Routine Special
Once in two Before and months Twice a after Before (Jan, year (April Once a Every monsoons and after March, month week & monsoons May, July, Twice during October) Sept., Nov. rains & Dec.
Check list of items required to be inspected durin 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 (vii) Horizontal clearances for poles carrying power and tele communication 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 stretch 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 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
Priority
Features concerned with safety of traffic: Any type of breach which Major breaches endangers safety of traffic and in the roadway causes obstruction to flow of traffic
Urgent
Cuts or blockades which do notGet blockades Minor cuts, ruts completely obstruct the traffic removed and get Urgent or blockades but endanger safety of trafficthe cuts repaired Branches of trees at height less than 4.5m over the roadway
Any kind
Get them cut in Special order of lower attention ones first
Feature
Criteria
Action
Priority
Carriageway and crust conditions: Local sealing or Cracking in local areas filling of the equal to or less than Routine cracks with slurry Cracking not 25% of the total area seal or fog seal accompanied by rutting Cracking in large areas Special exceeding 25% of the Surface dripping attention total area In local areas not exceeding 25% of the Apply local sealing total area Stripping
Apply surface In long areas exceeding dressing, use antistripping 25% of the total area compounds
Routine
Special attention
Feature
Bleeding
Criteria
Action
Priority
in local areas not Spread and roll over 6mm size exceeding 25% Routine aggregate, heated to 600c of the total area in local areas exceeding 25% of the total area
Apply surface dressing
Special attention
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 Rutting sealing of cracks More than 50mm Work of With surface dressing over accompanied by original cracks, overlay required cracking 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
Criteria
Deformation or scour of shoulders
Any extent
Silting of side drains
Any extent
Damage or scouring of drain
Any extent
Action
Priority
Fill and compact and bring its Routine surface to desired camber Clean out the drains
routine
Reconstruct to Special adequate shape attention and size
Maintenance criteria for C.D. works : causeways
Feature
Criteria
Potholes in paved Any surface extent Erosion at inlet/ outlet Guide posts/ flood gauge missing
Action
Priority
Repair by filling
Special attention
Any extent
repair
Special attention
Any
Repair/ replace
Special attention
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
Road furniture and warning signs Any dirty or corroded extent or damaged or missing Missing road signs any
Action
Priority
Clean and repair/ replace
routine
Fix new one
Special attention
Criteria for renewal
Renewal cycle of bituminous surfacing depends on traffic densit rainfall and lane width.
Type of renewal and periodicity of the renewal treatment for Low Medium Traffic rainfall rainfall Class Lane (comme up to 150 ––300 300 of road width rcial) 150 cm cm per per year year N.H.
Single
Less than 450
SD 4
SD 4
High rainfall above 300 cm per year 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
Fatty surface
Symptoms
Probable causes
Possible type of treatment
Excessive binder in Sand blinding; premix, spray open graded preCollection of or tack coat, mix; liquid seal binder on loss of coat; burning of the surface aggregates; excess binder; excessively removal of affected heavy axle area loads
Type of distress
Symptoms
Probable causes
Possible type of treatment
Smooth surface
Slippery
Polishing of aggregates Resurfacing with under traffic; surface dressing excessive or premix carpet binder
Streaking
Presence of alternate lean and heavy lines of bitumen
Non-uniform application of Application of a bitumen or at new surface a low temperature
Insufficient Short and fine The treatment will bitumen, Hairline cracks at close excessive filler depend on whether 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 series of small lower layers, cracks cracks. Unsound excessive over blocks cracked pavements will loads or brittleness of need strengthening or rehabilitation treatment binder
Longitudinal cracks
Edge cracks
Poor drainage The treatment will shoulder settlement, weak depend on whether joint between pavement is structurally Crack on a straight line adjoining spreads sound or unsound. Where the pavement is of pavement along the road structurally sound, the layers or differential frost cracks should be filled 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 direction or Shrinkage of pavement is structurally Shrinkage interconnected bituminous sound or unsound. cracks cracks forming alayer 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 cracksthe 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 Removal of the crescent Usual thrust of wheel in asurface layer in shaped cracks direction, lack or failure of the affected Slippage pointing in the bond between surface area and direction of theand lower pavement replacement thrust of courses with fresh wheels material
Rutting
Heavychannelised channelisedtraffic traffic Longitudinal inadequate compaction of depressionalininpavement layers, poor the wheel stability of pavement tracks material or heavy bullock cart traffic
Filling the depressions with premix material
Corrugations
Scarification Lack of stability in mix, and relaying of Formation oscillations set up by surfacings, of vehicles, springs or of regular cutting of high undulations faulty laying of surface spots and filling course of low spots
Shoving
Localised bulging of Unstable mix, lack of Removing the pavement bond between layers, or material to firm surface stop type movements base and along the and those involving relaying a crescent negotiation of curves stable mix shaped and gradients cracks
Shallow depressions
Localised Presence of Filling with premix shallow inadequately material depressions compacted pockets
Settlement and upheaval
Where fill is weaks, the defective fill should be Poor compaction of excavated and refills, poor drainage, Large done. Where inadequate deformation inadequate of pavement pavement or frost pavement is the heave cause, the pavement should be strengthened
Spreading and compacting heated Use of hydrophilic sand over the Separation of aggregate, inadequate affected area in the mix composition, bitumen case of surface Disintegrcontinuous contact from dressing; ation: aggregate in with water, poor bond replacement with Stripping between binder and the presence fresh bituminous aggregate, poor of moisture 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.,
Failure of binder Poor compaction, poor to hold the bond between binder Application of cutback covered with coarse aggregate shown and aggregate or Raveling up by pock marks insufficient binder, sand, or slurry seal or or eroded areas brittleness of binder, a premix renewal coat on the surface etc., Ingress of water into Appearance of the pavement, lack of Filling potholes with bowl-shaped bond between the Potholes premix material or holes, usually after surfacing and WBM penetration patching rain base, insufficient bitumen content, etc., Cutting the affected area to regular Water infiltration poor sections and reIrregular breaker lateral support from building with Edge of pavement shoulders, inadequate breaking simultaneous attention edges strength of pavement paid to the proper edges, etc., construction of s h o u ld e r s
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 retainin structures and parapets (iv) Keeping the sign boards, KM stones and other traffic ai 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 repair 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 frequency of inspection for condition survey
Type of road
N.H./ S.H.
E.E. Routine
Special
D.E.E. Routine
Special
Section I/C Routine Special
Once in two Before and months Twice a after Before (Jan, year (April Once a Every monsoons and after March, month week & monsoons May, July, Twice during October) Sept., Nov. rains & Dec.
Check list of items required to be inspected durin 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 (vii) Horizontal clearances for poles carrying power and tele communication 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 stretch 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 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
Priority
Features concerned with safety of traffic: Any type of breach which Major breaches endangers safety of traffic and in the roadway causes obstruction to flow of traffic
Urgent
Cuts or blockades which do notGet blockades Minor cuts, ruts completely obstruct the traffic removed and get Urgent or blockades but endanger safety of trafficthe cuts repaired Branches of trees at height less than 4.5m over the roadway
Any kind
Get them cut in Special order of lower attention ones first
Feature
Criteria
Action
Priority
Carriageway and crust conditions: Local sealing or Cracking in local areas filling of the equal to or less than Routine cracks with slurry Cracking not 25% of the total area seal or fog seal accompanied by rutting Cracking in large areas Special exceeding 25% of the Surface dripping attention total area In local areas not exceeding 25% of the Apply local sealing total area Stripping
Apply surface In long areas exceeding dressing, use antistripping 25% of the total area compounds
Routine
Special attention
Feature
Bleeding
Criteria
Action
Priority
in local areas not Spread and roll over 6mm size exceeding 25% Routine aggregate, heated to 600c of the total area in local areas exceeding 25% of the total area
Apply surface dressing
Special attention
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 Rutting sealing of cracks More than 50mm Work of With surface dressing over accompanied by original cracks, overlay required cracking 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
Criteria
Deformation or scour of shoulders
Any extent
Silting of side drains
Any extent
Damage or scouring of drain
Any extent
Action
Priority
Fill and compact and bring its Routine surface to desired camber Clean out the drains
routine
Reconstruct to Special adequate shape attention and size
Maintenance criteria for C.D. works : causeways
Feature
Criteria
Potholes in paved Any surface extent Erosion at inlet/ outlet Guide posts/ flood gauge missing
Action
Priority
Repair by filling
Special attention
Any extent
repair
Special attention
Any
Repair/ replace
Special attention
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
Road furniture and warning signs Any dirty or corroded extent or damaged or missing Missing road signs any
Action
Priority
Clean and repair/ replace
routine
Fix new one
Special attention
Criteria for renewal
Renewal cycle of bituminous surfacing depends on traffic densit rainfall and lane width.
Type of renewal and periodicity of the renewal treatment for Low Medium Traffic rainfall rainfall Class Lane (comme up to 150 ––300 300 of road width rcial) 150 cm cm per per year year N.H.
Single
Less than 450
SD 4
SD 4
High rainfall above 300 cm per year 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
Fatty surface
Symptoms
Probable causes
Possible type of treatment
Excessive binder in Sand blinding; premix, spray open graded preCollection of or tack coat, mix; liquid seal binder on loss of coat; burning of the surface aggregates; excess binder; excessively removal of affected heavy axle area loads
Type of distress
Symptoms
Probable causes
Possible type of treatment
Smooth surface
Slippery
Polishing of aggregates Resurfacing with under traffic; surface dressing excessive or premix carpet binder
Streaking
Presence of alternate lean and heavy lines of bitumen
Non-uniform application of Application of a bitumen or at new surface a low temperature
Insufficient Short and fine The treatment will bitumen, Hairline cracks at close excessive filler depend on whether 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 series of small lower layers, cracks cracks. Unsound excessive over blocks cracked pavements will loads or brittleness of need strengthening or rehabilitation treatment binder
Longitudinal cracks
Edge cracks
Poor drainage The treatment will shoulder settlement, weak depend on whether joint between pavement is structurally Crack on a straight line adjoining spreads sound or unsound. Where the pavement is of pavement along the road structurally sound, the layers or differential frost cracks should be filled 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 direction or Shrinkage of pavement is structurally Shrinkage interconnected bituminous sound or unsound. cracks cracks forming alayer 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 cracksthe 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 Removal of the crescent Usual thrust of wheel in asurface layer in shaped cracks direction, lack or failure of the affected Slippage pointing in the bond between surface area and direction of theand lower pavement replacement thrust of courses with fresh wheels material
Rutting
Heavychannelised channelisedtraffic traffic Longitudinal inadequate compaction of depressionalininpavement layers, poor the wheel stability of pavement tracks material or heavy bullock cart traffic
Filling the depressions with premix material
Corrugations
Scarification Lack of stability in mix, and relaying of Formation oscillations set up by surfacings, of vehicles, springs or of regular cutting of high undulations faulty laying of surface spots and filling course of low spots
Shoving
Localised bulging of Unstable mix, lack of Removing the pavement bond between layers, or material to firm surface stop type movements base and along the and those involving relaying a crescent negotiation of curves stable mix shaped and gradients cracks
Shallow depressions
Localised Presence of Filling with premix shallow inadequately material depressions compacted pockets
Settlement and upheaval
Where fill is weaks, the defective fill should be Poor compaction of excavated and refills, poor drainage, Large done. Where inadequate deformation inadequate of pavement pavement or frost pavement is the heave cause, the pavement should be strengthened
Spreading and compacting heated Use of hydrophilic sand over the Separation of aggregate, inadequate affected area in the mix composition, bitumen case of surface Disintegrcontinuous contact from dressing; ation: aggregate in with water, poor bond replacement with Stripping between binder and the presence fresh bituminous aggregate, poor of moisture 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.,
Failure of binder Poor compaction, poor to hold the bond between binder Application of cutback covered with coarse aggregate shown and aggregate or Raveling up by pock marks insufficient binder, sand, or slurry seal or or eroded areas brittleness of binder, a premix renewal coat on the surface etc., Ingress of water into Appearance of the pavement, lack of Filling potholes with bowl-shaped bond between the Potholes premix material or holes, usually after surfacing and WBM penetration patching rain base, insufficient bitumen content, etc., Cutting the affected area to regular Water infiltration poor sections and reIrregular breaker lateral support from building with Edge of pavement shoulders, inadequate breaking simultaneous attention edges strength of pavement paid to the proper edges, etc., construction of s h o u ld e r s
