Evaluation of pavement temperature on skid frictional of asphalt concrete surface

This paper presents the investigation of the effect of pavement surface temperature on the frictional properties of the pavement-tyre interface. Many skid tests were carried out on different wearing surfaces and under different climatic conditions using both ribbed and smooth tyres over 15 months. The pavement and air temperatures were obtained in each test using thermocouples located directly under the wearing course and close to the pavement surface, respectively. Regression analyses were carried out to determine the effect of pavement temperature on the measured skid number at different speeds, along with friction model parameters. The main conclusion of this investigation demonstrates that the pavement temperature has a significant effect on pavement frictional measurements and on the sensitivity of the measurements to the test speed. Both the skid number at zero speed (SN0) and the per cent normalised gradient tend to decrease with increased pavement temperature. At low speed, pavement friction tends to decrease with increased pavement temperature, and at high speed, the effect is reverted and pavement friction tends to increase with increasing pavement temperature. Temperature-dependent friction vs. speed models were developed for one of the mixes studied. These models could be used to define temperature correction factors.