Bidirectional heat induced structure of asphalt pavement for reducing pavement temperature

In order to reduce the solar absorption of pavement and accelerate the downward heat conduction, two bidirectional heat induced structures were designed, one named G-BHIS (only gradient thermal conductivity) and the other named G + R-BHIS (the combination of gradient thermal conductivity and heat reflective layer). Compared with the contrast structure, the heat absorption was reduced by 12.73% for the G-BHIS and 35.02% for the G + R-BHIS, respectively. The heat accumulation within the pavement was reduced by 15.9% for the G-BHIS and 37.6% for the G + R-BHIS, respectively. The coupling effect of the decreased heat absorption and accumulation reduced pavement temperature. The maximum temperature differences, 2.38 °C (for the G-BHIS) and 7.76 °C (for the G + R-BHIS), both appeared at the depth of 4 cm. Rutting results showed that the maximum rutting depth could be reduced by 41.0% for the G-BHIS and 65.0% for the G + R-BHIS, respectively. The two structures are expected to decrease heat accumulation and reduce pavement temperature, and furthermore, reducing rutting.