Interface between Tire and Pavement

Sliding friction between a pavement and tire is an important concern in traffic safety. The British pendulum test has been used worldwide to evaluate friction characteristics of pavement surfaces. However, because of considerable differences in apparatus, procedures, and operation, significant variability can occur for evaluations of British pendulum number (BPN). In this investigation, a direct shear test (DST) device is modified and proposed to determine the sliding friction coefficient between tire and pavement surface under dry and wet conditions. Dissipated energy values obtained from DST were compared with evaluations of BPN, and a high correlation was obtained. Tests were done using three types of pavement surface: asphalt concrete (AC), cement concrete (CC), and polymer concrete (PC), and two types of tires, namely ribbed and smooth. The proposed method of applying DST has the advantage of considering tire properties such as type, tread depth, and characteristics. Other advantages are consideration of the direct effect of vehicle weight and indirect effect of tire inflation pressure. Therefore, the friction characteristics measured by DST are close to reality. According to results of DST and BPN, the PC under dry and wet conditions had the highest and lowest evaluations for sliding friction coefficients, respectively. In addition, uniaxial compressive strength, abrasion resistance, and impact strength of pavement materials were determined. The PC mixture had the highest evaluations for ductility, compressive strength, abrasion resistance, impact toughness, and energy absorption.