热阻沥青混合料薄层罩面阻热性能研究

Study on Thermal Resistance Performance of Thermal Resistance Thin Surface of Asphalt Mixture

为了研究热阻沥青混合料薄层罩面的阻热作用,以低导热系数的陶粒替换普通石料设计SMA10热阻薄层罩面,采集混合料不同层位的温度,分析热阻薄层罩面对沥青混合料内部温度的影响,并从传热学角度对热阻薄层罩面的作用机理进行分析。研究结果表明:陶粒热阻罩面层可显著降低路面内部温度,陶粒掺量为0%、20%、40%、70%时,沥青混合料2cm层位处最大降温幅度分别为:2.7℃、7.5℃、8.4℃、21.6℃;8cm层位处最大降温幅度分别为:8.3℃、14.2℃、17.4℃、25.8℃。在密闭环境中,陶粒掺量过多在降低结构层内部温度的同时会引起表面层温度升高。因此,为了取得更好的降温效果,文中推荐热阻材料掺量为40%左右的薄层罩面。

To investigate the thermal resistance effect of the thermal resistance thin surface of asphalt mixture, the ordinary stone of thermal resistance thin surface SMA10 was replaced by ceramsite with low thermal conductivity coefficient, temperature of different layers was gathered, influences of internal temperature of thermal resistance thin surface on asphalt mixture were analyzed, and mechanism of thermal resistance was also analyzed by using heat transfer theory. The experimental results proved that interior temperature of pavement could be reduced remarkable by ceramsite thermal resistance thin surface. When ceramsite content were 0%, 20%, 40%, 70% respectively, cooling amplitude of asphalt mixture in 2 cm reached to 2. 7 ℃ ,7. 5 ℃ ,8. 4 ℃ ,21.6 ℃, respectively, and that of asphalt mixture in 8 cm reached to 8.3 C, 14. 2 ℃, 17.4 ℃ ,25.8 ℃, respectively. Interior temperature was reduced and superficial layer temperature was increased when ceramsite content was too much in closed environment. Therefore, 40% amount of thermal resistance materials was used in this study for the better cooling effect.