Effect Of Aggregate Type And Polishing Level On The Long-Term Skid Resistance Of Thin Friction Course

This study was attempted to investigate the influence of aggregate type and polishing level on the long-term skid resistance of thin friction course particularly with calcined bauxite. The PSV (Polished Stone Value) test, self-designed three wheel polishing device (TWPD) and dynamic friction tester (DFT) were applied to examine the friction performance of asphalt mixture and aggregate at different polishing cycles in laboratory. The mineral hardness of aggregate was linked with the skid resistance of aggregate and thin friction course by regression analysis. The grey correlation and t-test were utilized to evaluate the factors that influenced the skid resistance of thin friction course. It is found that better skid resistance value is observed for thin friction course by 88# calcined bauxite than by limestone, basalt and 75# calcined bauxite at each polishing level. PSV presents most significant influence for both terminal value and initial value of mu(60). The PSV attenuation rate of aggregate has a strong correlation with the attenuation rate of mu(40). The aggregate hardness parameter presents the ability of the aggregate and asphalt mixture to keep long-term skid resistance. In addition, calcined bauxite aggregate owns extensively applied potential in the thin friction course in China. (C) 2021 Elsevier Ltd. All rights reserved.