Performance-based specification guidelines for the selection of bituminous-based hot-poured crack sealants

The long-term performance of pavements depends in good part on the quality and frequency of maintenance. Appropriate maintenance protects the pavement from deterioration, corrects deficiencies, and ensures safe and smooth riding. Crack sealing is practiced on a routine basis as preventive maintenance and as part of corrective maintenance prior to an overlay or a greater rehabilitation project. A timely and properly installed sealant adds several years of service life to the pavement at a relatively low cost. As a consequence, the selection of an appropriate sealant in a maintenance project becomes an important issue. Current sealant selection is based on ASTM standards that consist of quality control tests, not of performance indicators. These standards do not consider the changes in mechanical properties due to aging or the differences in local service temperatures. The main purpose of this study was to develop a systematic process to help users to select appropriate bituminous hot-poured sealants for pavement cracks and joints. The tests include in this paper covering a summary of four years research project including an accelerated aging test, a viscosity test performed at installation temperatures, a dynamic shear rheometer (DSR) tests to assess tracking resistance in summer temperature, a crack sealant bending beam rheometer (CSBBR) and a crack sealant direct tension test (CSDTT) for cohesive properties at sub-zero temperature, and a blister test for adhesive properties.