PURPOSES : The aim of this study is to evaluate the stripping resistance of a bead coating via the Hamburg wheel tracking test and image analysis. METHODS : First, the stripping resistance of the bead coating was evaluated via the Hamburg wheel tracking test. A pneumatic wheel with a load of 175±2 N was used to simulate repeated skid cycles. Several bead coating mixtures with different numbers of coating layers, i.e., zero, one, two, three, and four layers, i.e., zero, one, two, three, and four layers,were conducted. Finally, an image analysis program was developed to analyze surface images captured from the Hamburg wheel tracking test. RESULTS : The results show that the samples with more coating layers exhibit higher stripping resistance. After 500 stripping cycles, the percentage of bead loss is 4% to 28%. At 80% bead loss, the mixture with one coating layer presents more skid cycles than the control sample without a coating layer. CONCLUSIONS : Incorporating a coating layer can improve the stripping resistance of glass beads under repeated skid cycles. Additionally, an image analysis program is established in this study to determine the percentage of bead loss caused by the stripping test.

The purpose of this study was to investigate the feasibility of converting the results obtained using different rutting performance tests. The correlation between the three simulation tests was analysed to determine the conversion coefficient factor. Two parameters (temperature and speed of simulation testing) were evaluated in this study. The results of this study have shown that the values obtained in the SALS test were lower than those obtained in the HWTT and UKWTT. The conversion of the SALS test results to the HWTT results yielded a good propensity value. The temperature is important parameter for determining the conversion coefficient factor.