Pooled Fund for Hot Applied Crack Seal

Project Description

Achieve a means of selecting durable crack sealant materials for use on pavements. The project will establish performance guidelines for the selection of crack sealants. The guidelines will be in the spirit of the Performance Grade (PG) system for bituminous binders with modifications to the testing equipment, data analysis procedure, and testing methods.

Research Activities Pursued This Year (Including Tasks):

• Completed specification testing for the viscosity measurements using the Brookfield Thermosel and studied the effect of temperature on viscosity measurements.
• Adapted aging procedure developed by NCR which permitted BBR and DTT testing on aged residue sealants.
• Developed specification testing to assess the BBR creep and recovery using a modified BBR test.
• Completed BBR testing of 10 crack sealants at three distinct temperatures.
• Identified 5 promising parameters obtainable from the modified BBR test that are being considered for inclusion in a performance-based specification. (Prony series expansion was used to stimulate and model BBR response to creep loading.)
• The Direct Tensile Tester (DTT) mold was modified to permit evaluation of sealant failure.
• Developed a semi-cylindrical adhesion fixture and conducted preliminary evaluation testing.
• Developed a fixture similar to "blister Test" to measure the work of adhesion and fracture energy of a sealant. The contact angles between several sealants and two types of aggregate were measured to determine the surface tension of each sealant.
• A modification has been made to the semi-cylindrical adhesion test fixture permitting testing to get underway.