CRACK TREATMENT OF FLEXIBLE PAVEMENTS Crack Sealing Routine

CRACK TREATMENT OF FLEXIBLE PAVEMENTS

Crack Sealing ØRoutine maintenance ØInvolves cleaning & sealing ØPrevents/reduces intrusion of v. Water v. Incompressible materials

Conditions for Success Type of maintenance depends on crack ØDensity ØSeverity ØPattern

Crack Treatment Design ØCrack Sealing Seal out water & incompressible materials ØCrack Filling Seal out water & preserve adjacent pavement

Working vs. Nonworking Cracks ØWorking crack moves more than 1/8 in. ØNonworking crack moves less than 1/8 in.

Sealing vs. Filling ØSealing For working cracks with limited edge deterioration ØFilling For nonworking cracks with moderate/no edge deterioration

SHRP Guidelines Crack Density Low Moderate High Edge Deterioration Low Moderate High None CT ? ? CR CT CT CR ST ST Rehab. CT = Crack Treatment (Sealing / filling) CR = Crack Repair Preventive Maintenance ST = Surface Treatment

High Density, Moderate Edge Deterioration

Moderate Density, High Edge Deterioration

Low Density, Moderate Edge Deterioration

Low Density, Moderate Edge Deterioration (Nonworking)

Sealing/Filling Materials Ø Cold applied thermoplastic Ø Hot applied thermoplastic Ø Chemically cured thermosetting

Thermoplastics ØAsphalt has little flexibility & very temperaturesusceptible ØRubber & other additives improve flexibility

Chemically-Cured Thermosettings ØCure by chemical reaction from liquid to solid ØSelf-leveling silicon is an example

Sealing Configurations ØFlush-fill ØReservoir ØOverband ØCombination: Reservoir and overband

1/2 – 3/4 in.

3 - 5 in.

Crack Treatment Procedure ØCrack routing (Optional) ØCrack cleaning & drying ØMaterial preparation & application ØMaterial finishing/shaping (Optional) ØBlotting (Optional)