Slide 1Instructional ObjectivesNeed for Condition SurveysTypes of SurveysDistress SurveysDistress Surveys TypesPaserPaser Distress-AsphaltPaser Distress-ConcreteLTPP DistressLTPP Distress-AsphaltLTPP Distress-ConcretePaver DistressPaver Distress-AsphaltPaver Distress- ConcreteRide Quality IRI (International Roughness Index)ROUGHNESS SURVEYIRI CALCULATIONRide Quality RUT DEPTH MEASUREMENTWHAT IS REPORTED?SAMPLE DATA AGGREGATIONStructural CapacityStructural Evaluation Destructive TestingStructural Evaluation Non-Destructive TestingAutomated Distress SurveysAutomated Condition Survey EquipmentClasses of Automated Data CollectionRolling Weight DeflectometerSlide 29Slide 30Distress Data CollectionDrainage SurveysPavement failure is caused by:Signs of Deficient DrainageHow Much Data to Collect?Network SamplingSection SamplingFrequency of SurveysSlide 39PAVEMENT CONDITION SURVEYSLecture 4Instructional ObjectivesNeed for condition surveysCollection methodologiesFour basic types of condition surveysDifferent procedures and equipment availableNeed for Condition SurveysEvaluate current condition of pavementDetermine rates of deteriorationProject future conditionsDetermine maintenance & rehabilitation needsDetermine costs of repairsPrepare plans for repairsTypes of SurveysDistress SurveysStructural CapacityRoughness (Ride Quality)Skid Resistance (Surface Friction)Distress SurveysType of distressSeverityExtent of distress present on the pavementDistress Surveys TypesPaserPaverSHRPAsphalt InstituteTexas Transportation InstitutePaser Asphalt ConcreteGravel RoadsPaser Distress-AsphaltUses visual inspection techniquesSurface defectsSurface deformationCracksPatches and potholesPaser Distress-ConcreteUses Visual inspection techniques—Surface defects—Joints—Pavement cracks—Pavement deformationLTPP DistressAsphaltConcreteLTPP Distress-AsphaltCrackingPatching and potholesSurface deformationsSurface defectsMisc distressLTPP Distress-ConcreteCrackingJoint deficienciesSurface defectsMisc distressesPaver Distress AsphaltConcretePaver Distress-AsphaltAlligator crackingBlock crackDistortionsLongitudinal and transverse crackingPatching and utility cutsRuttingPaver Distress- ConcreteBlow-ups and BucklingCorner breakD crackingLinear crackingPolished aggregatePumpingRide QualityIRI (International Roughness Index)IRI is calculated from longitudinal profile measured with a road profiler in both wheelpaths. The average IRI of the two wheelpaths is reported as the roughness of the pavement section.ROUGHNESS SURVEYSurvey the outside lane.For undivided highways survey one direction.For divided highways survey the outside lane in both directions.For each survey cycle use the same direction(s) of travel and survey lane(s).IRI CALCULATIONInternational Roughness Index (IRI) - The IRI is computed from a single longitudinal profile using a quarter-car simulation as described in the report, "On the Calculation of IRI from Longitudinal Road Profile." [Sayers 95]Ride QualityRUT DEPTH MEASUREMENT1.7 m3 RuttingSensorsWHAT IS REPORTED?3 P o i n t M e a s u r e m e n t e v e r y 1 5 . 0 m e t e r s8 6 0 m m8 6 0 m mR u t D e p t hD DD2 312D2D1D3SAMPLE DATA AGGREGATION051015202530354045Level 1 Level 2Level 3 Level 4 Severity LevelPercent of Measurements within the SectionStructural CapacityNot routinely collected for pavement monitoringMainly used for selecting and designing rehabilitation strategiesCan reduce maintenance and rehabilitation costsStructural EvaluationDestructive TestingCoringLaboratory testingExcavation of pitsField CBRStructural EvaluationNon-Destructive TestingBenkelman BeamDynaflectRoad RaterFWDRolling DeflectometerGPRAutomated Distress SurveysIncrease speed and ease of data collectionReduce transcription errorsIncrease consistency between classification and quantificationIncrease safety of field crewsAutomated Condition Survey EquipmentUsed by most states to collect:–Pavement friction–Roughness–Profile–Rut depth–Deflection dataClasses of Automated Data CollectionDistress images collected on film or high resolution video and:–analyzed while the vehicle collects data–analyzed in the office after data collection–analyzed after data collection by viewing the imagesLasers are used to determine changes in surface textureRolling Weight DeflectometerPrimary objectives are:–Develop an RWD suitable for network level analysis–Collect data at speeds of 50 mph–Output will be a structural index–Measure maximum deflection, pavement temperature, station numbers, and day and time of testRolling Weight DeflectometerPhase I –Identified deflection measurementsPhase II–Highway speeds–Deflection response converted to a structural indexRolling Weight DeflectometerObjective is to compare relative structural strengthsIdentify weak linksDeflection basins, magnitudes, loads and temperaturesProcessed in real timeContinuously measured at 1 foot intervalsDistress Data CollectionVisual surveyLaser technologyFilm-based systemsVideo systemsDrainage SurveysPoor drainage causes poor pavement performanceWater on a pavement can:–create a hazard to motorists–saturate the subgrade soil–deteriorate the pavementPavement failure is caused by:Load–Load capacity can be increased by an overlayMoisture–If proper drainage is not provided during rehabilitation, the same moisture related distress will recurSigns of Deficient DrainageStanding water in ditchlinesConcentrated weed growth in ditchline or edge of pavementEvidence of water ponding on shoulderDeteriorated joint or crack sealantsAny evidence of pumpingHow Much Data to Collect?To support network-level analysis–Sampling processesTwo sampling procedures:–Network sampling–Section samplingNetwork SamplingLess samples needed when total number in the whole increasesTo determine average condition:–Sample 2 - 5%To predict the distribution of condition:–Sample 10 - 25%To predict cost of repairs, restorations:–Sample 30 - 35%Most states survey 10%Section SamplingTo identify sections of pavement in a selected condition level, the condition of each section must be definedIf a windshield survey is used:–entire section should be inspectedIf a walking or automated survey is used:–a portion of
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