Using Shotblasting Treatment To Improve Asphalt Pavement Friction At The Ncat Test Track

The objective of this study was to examine the effectiveness of using shotblasting treatment to improve surface friction of asphalt pavements. The National Center for Asphalt Technology (NCAT) Test Track is a 1.7-mile oval where the accelerated loading research is conducted on experimental asphalt pavements. In this study, six pavement sections with low skid resistance were selected for shotblasting abrasion, which included three surface mixture types (open-graded friction course and dense-graded asphalt with and without reclaimed asphalt pavement material) and four aggregate types (limestone, granite, dolomite, and sandstone). The dynamic friction tester and lock-wheel skid trailer were used to measure surface friction of these sections at the different traffic polishing cycles. In addition, the pavement performance including rut depth, cracking, and surface roughness was periodically monitored. The test results indicated that shotblasting treatment was effective in improving the long-term friction performance of asphalt pavements and had no detrimental impact on pavement performance in terms of cracking, rutting, and surface roughness. The friction improvement by shotblasting treatment was significantly dependent on surface mixture type and aggregate type.