DistressMode TypesofCracks Description Attributes PossibleCauses RecommendedRemedies

Interconnectedcracksformingseries Predominantcrackwidth(mm) Insufficientslabthickness Narrowcrackssealing

BlockCracks ofblocksrectangularshape Predominantcellwidth(mm) Settlementofsubbase/subgrade Stitchedcrackrepair
Areaaffected(m2) Advancestageinpavementlifecycle Widecracksbayreplacementrepair/fulldepthrepair
Cracklinkingatransversejointtoslab Crackwidth(mm) Lackofloadtransferjoints Corner/transversefulldepthrepair
edge/longitudinaljoint Cracklength(m) Dowelbarrestraintnearedgeofslab
CornerCracks No.ofslabsaffected Ingressofsolidsintojointatslabedge
Lossofsubbasesupport
Multidirectionalcracks(not Crackwidth(mm) Shrinkageofslabduringcuring(jointssawntoolate) Narrowcrackssealing
transverse/longitudinal/acrosscorners Cracklength(m) Settlementofsubbase/subgrade Stitchedcrackrepair
DiagonalCracks ofbays) No.ofslabsaffected Rockingofslab Widecracksbayreplacementrepair/fulldepthrepair
Insufficientslabthickness

Unconnectedcrackrunning Crackwidth(mm) Differentialsettlement Narrowcracks(reinforcedslabs)noaction

longitudinally Cracklength(m) Lateralshrinkage(relatedtoexcessiveslabwidth) Narrowcracks(unreinforcedslabs)/mediumcracksstitched
Cracking LongitudinalCrcks Crackspacing(mm) crackrepair
Areaaffected(m2) Widecrackslongitudinalfulldepthrepair/bayreplacement
repair
Short/obliqueindrection(don'textend Predominantcrackwidth(mm) Inadequatecuring Sealingcracks
toslabedge).Initiallyshallowdepth Cracklength(m) Fulldepthrepair
Concrete
butaftersubsequentheatingand No.ofslabsaffected Bayreplacementrepair
Pavement
ShrinkageCracks cooling,wettinganddrying,crackswill
extendacrossfulldepthslab

Crack/breakrunningtransversely Crackwidth(mm) Dowelbarrestraintsatjoints Mediumcracksgroovingandsealing

acrosspavement/slab Cracklength(m) Subbaserestraint(lackofseparationlayer/irregularityofsubbase Widecrackstransversefulldepthrepair
TransverseCracks Crackspacing(mm) Insufficientslabthickness Fullbayreconstruction
Areaaffected(m2) Unmatchedjointsin2parallelslabs

Differentialverticaldisplacementof Differenceinelevation(mm)acrossjoint Lackofeffectiveloadtransferdowel&tiebaratjoints/cracks Totalslabreconstructionandsubgrade

JointStepping abuttingslabsatjoints/cracks crack Poorsubbase/subgradesupport Slabliftingbypressureorvacuumgrouting
No.ofslabsaffected Lossofsubbasematerialduetopumping
Deformation
Verticalmovementatjointswhen Can'tbequantified Lackofsubbasesupport Fulldepthreconstruction
Rocking vehiclespassover Lackof/ineffectiveloadtransferdowelortiebarsatjoints Pressure/vacuumgrouting

Loss/crackingofseal.Extrusionof Percentage(bylength)ofjointaffected AdhesivefailureMoistureinsealinggroove Removeoldseal,cleanoutandreseal

JointSealant JointSealantDefects sealantleavingmouldatjoint CohesionfailureLackofbondbreakingstripbeneathseal
ExtrusionOverfilledsealinggroove

Others:SurfaceSpalling,BoxoutSpalling,LossofSurfaceTexture
 DistressMode TypesofCracks Description Attributes PossibleCauses RecommendedRemedies
Interconnectedcracksformingaseries Predominantcrackwidth(mm) Hardening&shrinkageofbit.Material Coldmilling&resurfacing
oflargepolygons.Sizerange:200 Predominantcellwidth(mm) Fatiguecrackinginwearingcourse Fulldepthreconstruction
BlockCracks
3000mm Areaaffected(m2) Hotinplacerecycling

Interconnected/interlacedcracks. Predominantcrackwidth(mm) Saturatedbase/subgrade Fulldepthreconstruction

Associatedwithwheelpathsand Predominantcellwidth(mm) Ruptureofsurfacecourseduetotrafficload,fatigue,ageing Deepinlay
CrocodileCracks resilientsubgrade.Sizerange150 Areaaffected(m2) Inadequatepavementthickness Hotinplacerecycling
300mm Sealingwithemulsion&sand

Unconnectedcracktakingdiagonalline Predominantcrackwidth(mm) Reflectionofashrinkagecrack/jointinunderlyingcementedmaterial Fillandsealcrackwithhotbitumen/approvedcracksealant

acrosspavment Length(m) Differentialsettlementbtwnembankments,cutsorstructures Coldmillandresurface
DiagonalCracks Areaaffected(m2) Treeroots
Serviceinstallation

Crackrunninglongitudinally(singlyor Widthofdominantcrack(mm) Occurringsingly(poorlongitudinaljointconstruction,differential Fillandsealcrackwithhotbitumen/approvedcracksealant

Cracking
asseries) Lengthofdominantcrack(m) movmentduetopavementwidening,bitumenhardening) Coldmillandresurface
LongitudinalCracks Spacing(mm) Occurringseries(Volumechangeofexpansiveclaysubgrade, Improvementofslopestability
Areaaffected(m2) differentialsettlementofsubgrade) Sufficientlateralsupporttoroadexcavation

Halfmoon/crescentshapedcrackin Predominantcrackwidth(mm) Inadequatebondofwearingcoursewithunderlyinglayer.Insufficient Removesurfacelayerfromaroundcrack.Squareupandpatch

trafficdirection(aka.shearcrack) Areaaffected(m2) wearingcoursethickness.Inadequatebondduetodust,dirt,oil areawithhotmixbituminousmaterial
Slippageofwearingcourse
SlippageCracks
Lowmodulusbasecourse

Transverseruptureacrosspavement Widthofdominantcrack(mm) Constructionjointorshrinkagecrack(duetolowtemp./bitumen Fillandsealcrackwithhotbitumen/otherapprovedcrack

Bituminous forbit.Surfacingoverbridge Length(m) hardening)insurfacecourse sealant
Pavement TransverseCracks deck/concreteslabs.Crackreflect Spacing(mm) Reflectioncrackingfromconcretebase
movementreflectioncrack Areaaffected(m2) Movementofunderlyingpavement

Localisedareawithelevationslower Max.depthunder1.2mstraightedge Settlementofservicetrenches Utilityundertakingtorectify

thansurroundingarea. (mm) Consolidationofisolatedareasofsoft/poorlycompactedsubgrade Patchingtorestoretheareatosamegrade
Depression Areaofdepression(m2) Settlementduetoinstabilityofembankment Excavatelocallydownintofill/poorlysubgradeandreplace
withnewcompactedfill/pavement
Longitudinaldeformationina Max.depthundertransverse1.2m Inadequatecompactioninsurface/base Levellingpavementbyregulatingcoursefollowedbybit.
Deformation Rutting wheelpath(aka.Channelling) straightedge(mm) Settlementofunderlyingcourse/subgradeundertraffic Overlay
Length(m) Structuralfailureofsubgrade Localisedreconstructionwithconcrete

Bulgingofroadsurfaceandhorizontal Max.depthofbulgeunder1.2m Inadequatestrengthofsurfacing/base Squareupandremoveshovingforfulllayerdepthfollowedby

displacmentofsurfacingmaterials straightedge Poorbondbetweenpavementlayers patchingwithstiffermaterial
Shoving wherebraking/accelerationoccur Areaaffected(m2) Lowvoidcontentinsurfacing

Progressivedisintegrationbylossof Areaaffected(m2) Separationofbituminousfilmfromagg.duetowateractionor Coldmilling&resurfacing

binderandagg. mechanicalforces Squarepatching
SurfaceTexture Disintegrationofagg. Hotinplacerecycling
Ravelling
Defiencies Poorconstruction(segregation,faultymixdesign,overheatingmix,bad
compaction,inadequatecoating)

Irregularlyshapedholesinvarioussize Depthofpotholes(mm) Developingfromanotherdefect(e.g.toothinsurfacelayer,toomany Temporaryrepairinvolvescleaningholeandfillingwithinstant

Areaofpothole(m2) finesresultingdisintegrationwithremovalofmaterialbytrafficover holefillingmaterial/bit.Wearingcoursematerial
Potholes Potholes No. weakenedspots) Squarepatching
Moistureentrytobasecoursethroughcrackedsurface Hotinplacerecycling

Others:Corrugations,Flushing,Polishing,Delamination,KerbDefects