Failures in pavements.ppt

7/26/2019 Failures in pavements.ppt

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Failures in pavementsFailures in pavements


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Need for highway maitenanceNeed for highway maitenance

Maintenance InvolvesMaintenance Involves

Assessment of road conditionAssessment of road condition

Diagnosis of problemDiagnosis of problem


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General causes of pavement failuresGeneral causes of pavement failures

Defects in quality of materialsDefects in quality of materials

Defects in construction methodDefects in construction method

Inadequate surface or subsurface drainageInadequate surface or subsurface drainage Increase in wheel loads and repetition of loadsIncrease in wheel loads and repetition of loads

due to increase in trafficdue to increase in traffic

Settlement of foundation of embankmentSettlement of foundation of embankment Environmental factors like heavy rain, waterEnvironmental factors like heavy rain, water

table frost, snowtable frost, snow


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TYPES OF M!NTENN"ETYPES OF M!NTENN"E

he maintenance activities are divided intohe maintenance activities are divided into

two categories!two categories!

"reventive maintenance"reventive maintenance

#orrective maintenance#orrective maintenance


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"reventive maintenance activities includes"reventive maintenance activities includes

repairs to small si$ed potholes, crack sealing,repairs to small si$ed potholes, crack sealing,

maintenance of shoulders, drainage systems,maintenance of shoulders, drainage systems,

etc%etc%

#orrective maintenance includes patch#orrective maintenance includes patch

repairs, surface treatments, renewal andrepairs, surface treatments, renewal and

overlaysoverlays


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#lassification of Maintenance#lassification of Maintenance

ActivitiesActivities

As per I ! '(, maintance operations can be classifiedAs per I ! '(, maintance operations can be classifiedasas

#outine maintenance#outine maintenance) *rdinary &epairs) *rdinary &epairs&outine maintenance, such as , pothole filling, filling&outine maintenance, such as , pothole filling, fillingthe cracks, etc% round the year%the cracks, etc% round the year%

Periodic maintenancePeriodic maintenance

"eriodic maintenance covering renewals, which are"eriodic maintenance covering renewals, which arerequired to be done at periodic interval every fewrequired to be done at periodic interval every fewyears%years%


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Maintenance management systemMaintenance management system

Minimum standards for maintenance ofMinimum standards for maintenance of

different categories of roadsdifferent categories of roads

+ield survey for evaluation of maintenance+ield survey for evaluation of maintenancerequirementsrequirements

Sub grade soil, drainage, climaye, traffic,Sub grade soil, drainage, climaye, traffic,

environmental conditionenvironmental condition


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#lay soil- plastic deformation#lay soil- plastic deformation

Improper compaction . consolidationImproper compaction . consolidation

deformationdeformation


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Failures in su%%ase or %ase courseFailures in su%%ase or %ase course

Inadequate stability or strengthInadequate stability or strength

/oss of binding action/oss of binding action

/oss of base course materials/oss of base course materials Inadequate wearing courseInadequate wearing course

0se of inferior materials0se of inferior materials

/ack of lateral confinement/ack of lateral confinement


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!nade&uate Sta%ility or Strength'!nade&uate Sta%ility or Strength'

((

"oor Mi proportioning or inadequate"oor Mi proportioning or inadequate

thickness are main reasons for the lack ofthickness are main reasons for the lack of

stability or strength of sub-base or base course%stability or strength of sub-base or base course%


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)se of inferior materials)se of inferior materials

Many failures, mainly structural failure areMany failures, mainly structural failure are

attributed due to use of inferior materials in theattributed due to use of inferior materials in the

passing 3obs%passing 3obs%

*ac+ of lateral confinement for the granular*ac+ of lateral confinement for the granular

%ase course'%ase course'

Due to lack of lateral confinement of granularDue to lack of lateral confinement of granular

base course, deterioration occurs%base course, deterioration occurs%


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5ormally, the affected area is not large%5ormally, the affected area is not large%

2hen it does occur on a large scale, the2hen it does occur on a large scale, the

cracking is most likely due to repeated loadscracking is most likely due to repeated loads

above the designed strength of the pavementabove the designed strength of the pavement


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reatmentreatment

1ecause a structural failure is taking place the1ecause a structural failure is taking place the

only possible solution to alligatoring is toonly possible solution to alligatoring is to

perform a full-depth patch%perform a full-depth patch%


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reatmentreatment

/ess severe cracks measuring 8)( inch or less/ess severe cracks measuring 8)( inch or less

can be sealed to prevent moisture fromcan be sealed to prevent moisture from

entering into the sub grade%entering into the sub grade%

More severe cracks should be fied byMore severe cracks should be fied by

removing the cracked pavement layer andremoving the cracked pavement layer and

replacing it with an overlay%replacing it with an overlay%


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ransverse #rackingransverse #racking

ransverse cracks are single cracksransverse cracks are single cracks

perpendicular to the pavement9s centerline orperpendicular to the pavement9s centerline or

laydown direction%laydown direction%

ransverse cracks can be caused by reflectiveransverse cracks can be caused by reflective

cracks from an underlying layer, dailycracks from an underlying layer, daily

temperature cycles, and poor construction duetemperature cycles, and poor construction due

to improper operation of the paver%to improper operation of the paver%


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reatmentreatment

/ess severe cracks measuring 8)( inch or less/ess severe cracks measuring 8)( inch or less

can be sealed to prevent moisture fromcan be sealed to prevent moisture from

entering into the sub grade%entering into the sub grade%

More severe cracks should be fied byMore severe cracks should be fied by

removing the cracked pavement layer andremoving the cracked pavement layer and

replacing it with an overlay%replacing it with an overlay%


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Edge #racksEdge #racks

Edge #racks travel along the inside edge of aEdge #racks travel along the inside edge of apavement surface within one or two feet%pavement surface within one or two feet%

he most common cause for this type of crack ishe most common cause for this type of crack is

poor drainage conditions and lack of support at thepoor drainage conditions and lack of support at thepavement edge%pavement edge% As a result underlying base materials settle andAs a result underlying base materials settle and

become weakened%become weakened%

4eavy vegetation along the pavement edge and4eavy vegetation along the pavement edge andheavy traffic can also be the instigator of edgeheavy traffic can also be the instigator of edgecrackingcracking


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Slippage #racksSlippage #racks

Slippage cracks are crescent-shaped cracks orSlippage cracks are crescent-shaped cracks or

tears in the surface layer6s7 where the newtears in the surface layer6s7 where the new

material has slipped over the underlyingmaterial has slipped over the underlying

course%course%

his problem is caused by a lack of bondinghis problem is caused by a lack of bonding

between layers%between layers%


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reatmentreatment

All of the areas ehibiting the :stretch marks;All of the areas ehibiting the :stretch marks;

will need to be removed and will require awill need to be removed and will require a

partial or full depth patch%partial or full depth patch%


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As alligator cracking becomes severe, theAs alligator cracking becomes severe, the

interconnected cracks create small chunks ofinterconnected cracks create small chunks of

pavement, which can be dislodged as vehiclespavement, which can be dislodged as vehicles

drive over them%drive over them% he remaining hole after the pavement chunkhe remaining hole after the pavement chunk

is dislodged is called a pothole%is dislodged is called a pothole%


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DepressionsDepressions

Depressions are locali$ed pavement surfaceDepressions are locali$ed pavement surface

areas with slightly lower elevations than theareas with slightly lower elevations than the

surrounding pavement%surrounding pavement%

Depressions are very noticeable after a rainDepressions are very noticeable after a rain

when they fill with water%when they fill with water%


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h l


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0pheaval0pheaval

0pheaval is a locali$ed upward movement in a0pheaval is a locali$ed upward movement in a

pavement due to swelling of the subgrade%pavement due to swelling of the subgrade%

his can be due to epansive soils that swellhis can be due to epansive soils that swell

due to moisture or frost heave 6ice under thedue to moisture or frost heave 6ice under the

pavement7%pavement7%


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reatmentreatment

+ull depth patch+ull depth patch


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Sealing of #racksSealing of #racks''

he cracks are opened and cleaned withhe cracks are opened and cleaned with

brush%brush%

ack coat of hot bitumen is then appliedack coat of hot bitumen is then applied

under pressure to fill-up the cracks%under pressure to fill-up the cracks%

he treated surface is then covered withhe treated surface is then covered with

premi material%premi material%


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4air cracks can be repaired by applying slow4air cracks can be repaired by applying slow

setting emulsion evenly at the rate of ? to @setting emulsion evenly at the rate of ? to @

kg)sqm%kg)sqm%

/ight tamping to the coat of bituminous/ight tamping to the coat of bituminous

emulsion is recommended%emulsion is recommended%


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Date post:	01-Mar-2018
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Failures in pavements.ppt

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