Effects of thermally modified asphalt concrete on pavement temperature

AbstractThis study investigates the feasibility of mitigating temperature-related issues, such as heat island effect, ice layer formation and thermal distresses of asphalt pavement, by controlling thermal properties of hot mix asphalt (HMA). Expanded polypropylene (EPP) beads and graphite powder are selected as the additives to change the thermal properties of HMA, and their effects on thermal and mechanical properties are evaluated experimentally. The test results show that the EPP modified HMA yields a reduction in thermal conductivity, heat capacity and indirect tensile strength up to 17, 32, and 27%, respectively. Conversely, replacing a part of traditional fillers with graphite powder increases indirect tensile strength and thermal conductivity up to 40 and 43%, respectively. A series of heat transfer analysis was conducted using a finite difference heat transfer model to investigate the effects of the thermally modified HMA on the pavement temperature gradient and surface temperature. The simulation...