RELATIVE PERFORMANCE OF CRACK SEALING MATERIALS AND TECHNIQUES FOR ASPHALT PAVEMENTS

The Western Transportation Institute - Montana State University in conjunction with the Montana Department of Transportation is conducting research to determine the most economical materials and techniques for sealing cracks in asphalt pavements. Four experimental test sites were established on interstate highways in western Montana to study the behaviors of nine sealant materials and six placement techniques. The nine sealant types used in this study were all single-component, hot-applied materials that varied in stiffness and resilience. All test sites were visually inspected for various modes of material failures that permit water to penetrate sealed cracks into the pavement structure. Statistical forecasting of measured distresses was used to estimate the useful life of multiple material/technique combinations. In addition to conducting visual inspections, the evaluation of a test site near Helena, Montana included nondestructive testing using a falling-weight deflectometer (FWD). Results from these tests were used to compare pavement stiffness values between the sealed test sections and an unsealed control section.