Investigation of the raveling potential of thin friction course (TFC) under freeze–thaw conditions

Abstract

The thin friction course (TFC), consisting of modified asphalt emulsion, single particle size aggregate, and cement, is usually utilized as a preventive maintenance treatment to address the functional distresses of asphalt pavement. Meanwhile, TFC materials also face harsh environmental and traffic conditions, especially the freeze–thaw conditions in the cold region. To mitigate the freeze–thaw induced raveling distress of TFC, specimens with varying design parameters were evaluated by wet track abrasion test. Besides, the bond strengths of asphalt-aggregate systems with varying design parameters were assessed by the binder bond strength (BBS) test. According to the results, the increased emulsion and moderate styrene butadiene rubber (SBR) dosages are beneficial to improving the raveling resistance of TFC. The addition of cement can reduce the initial aggregate loss of TFC but will also increase the susceptibility under freeze–thaw conditions. In addition, SBR latex can mitigate the freeze–thaw induced damage of pull-off strength tested in the BBS test. Finally, according to correlation analysis, the pull-off strengths of specimens with varying SBR contents only, have the best correlation with the raveling potential of TFC, with a correlation coefficient of 0.715. Thus, the BBS test is capable to distinguish the retention performance of TFC with varying SBR additions.