Simulation of the Cooling Effect of Porous Asphalt Pavement with Different Air Voids

Abstract

Porous asphalt pavement shows lower internal temperature than does dense-graded asphalt pavement under high temperature conditions in summer. To study the cooling effect of porous asphalt pavement, the thermophysical properties of a dense-graded asphalt concrete (AC) mixture and a porous asphalt concrete (PAC) mixture were determined using a parallel model. Then, a laboratory-simulated sunshine experiment was carried out, and the convective heat transfer coefficients of specimens were inferred by virtual experiment. Lastly, the temperature field distribution simulation of PAC pavement was analyzed. The results show that the thermophysical properties of the PAC-13 mixture are lower than those of the AC-13 mixture; the larger the proportion of air voids, the greater the difference appears. Under windy conditions, the convective heat transfer coefficients of the PAC specimen surfaces are higher than those of AC specimens, and the convective heat transfer coefficient of the specimen surface shows an upward trend with increasing air voids. The cooling effect of the porous pavement increases with increasing proportion of air voids, and the cooling effect of the porous asphalt pavement is better than that of the dense-graded asphalt pavement. There is a good positive linear correlation between cooling effect and air voids, and mathematical models between them which can provide an important reference for PAC pavement design were fitted.