Modeling the Frictional Performance of Asphalt Mixtures Based on the British Pendulum-Accelerated Polishing Wheel Lab Testing

ABSTRACT

It is vital to ensure that an adequate surface texture (skid resistance) between vehicle tires and pavement surface is available throughout the pavement service life. The surface microtexture and macrotexture properties control the pavement surface skid resistance. This study aimed to propose a simple laboratory approach for evaluating the microtexture properties of asphalt mixtures using the British pendulum tester-accelerated polishing wheel combination (BPW–BPT). As part of this effort, a simple sample procedure was introduced to prepare asphalt mixture coupons compatible with the BPW. The BPT results obtained from these asphalt mixture coupons were also validated by comparing them with the dynamic friction tester (DFT) results at 20 km/h (DFT20) from laboratory-produced slabs. Subsequently, the international friction index and skid number (SN[50]) models were revised and optimized to replace DFT20 with the BPT values of mixture coupons. A good linear correlation between the BPT and DFT20 results was found with an overall coefficient of determination (R2) of around 0.92. In addition, the results of the proposed testing procedure were used to develop an empirical model to predict the SN(50) with an accuracy of 0.942. Finally, the proposed laboratory testing procedure offers a simple, practical approach for evaluating the friction properties of asphalt mixtures and facilitates the integration of friction assessment into asphalt mix design.