气孔玄武岩超薄罩面沥青路面降温效果和性能研究

为了缓解城市热岛效应和降低沥青路面温度,在NovaChip型超薄罩面沥青混合料中掺入气孔玄武岩,采用自行研发的室内模拟热辐射系统对车辙板试件进行照射并采集不同层位处温度,对比不同气孔玄武岩掺量下的沥青混合料降温性能和路用性能。研究结果表明:随着气孔玄武岩体积掺量的增加,试件的上表面温度逐渐升高;相比较于0%掺量,25%、50%和75%掺量下试件2 cm处最大降温分别为2.0 ℃、4.2 ℃和5.9 ℃,试件底面最大降温分别为2.4 ℃、5.1 ℃和6.6 ℃,导热系数降低了39.1％、50.7％和61.8％;随着气孔玄武岩掺量的增加,沥青混合料的高温性能适当提高,低温性能几乎不变,水稳定性能降低,抗滑性能先增加后降低;最终综合降温性能和水稳定性能确定了气孔玄武岩推荐体积掺量为25%~30%。

Temperature Reduction and Performance of Asphalt Pavement with Stomatal Basalt Ultra-Thin Overlay

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%.