Abstract: To mitigate the effect of the urban heat island and lower asphalt pavement temperature, the stomatal basalt was added into the NovaChip type ultra-thin overlay asphalt mixture in the current study. The indoor simulation thermal radiation system was used to irradiate the specimen, the temperature variance was collected at different layers, and the cooling effect of the asphalt mixture with different basalt content was compared. The results show that the upper surface temperature of the test specimen increase with an increase in the volume content of stomatal basalt. Compare with 0% mixing amount, the cooling effect of asphalt mixtures with 25％, 50％ and 75％ content of stomatal basalt is relatively good, their temperatures at 2 cm inside dorp are 2.0 ℃, 4.2 ℃ and 5.9 ℃, their temperatures under the bottom dorp are 2.4 ℃, 5.1 ℃ and 6.6 ℃, respectively. The thermal conductivity decrease 39.1％, 50.7％and 61.8％. As the proportion of stomatal basalt increases, the high temperature stability of the asphalt mixture improves, the low-temperature performance is almost invariable, the water stability decreases, and the sliding resistance increases first and then decreases. Overall, considering cooling effect and pavement performance variance, the proportion of stomatal basalt in the asphalt volume content is proposed as 25% to 30%.

Key words: thermal resistance ultra-thin overlay, stomatal basalt, asphalt mixture, cooling performance, thermal conductivity, pavement performance