Frictional properties of asphalt concrete mixes

Skid resistance is an important factor in pavement performance because it is related to safety. It is controlled by the micro- and macrotexture of the pavement surface. The purpose of the study described herein was to identify variables related to the friction performance of surface asphalt mixes in order to optimise material selection and to provide information for the development of improved mix designs. This study evaluated the friction values of 72 asphaltic surfaces including open-, gap- and dense-graded mixes at different ages. Microtexture was measured using a British Pendulum Tester and macrotexture was measured by a high-speed laser profiler. Statistical models were developed for micro- and macrotexture using climate, traffic and pavement mix variables. Results indicated that microtexture is affected by temperature, age, and traffic whereas macrotexture is affected by rainfall, freeze–thaw cycles and pavement mix variables.