透水沥青混合料的热物特性与热阻功能

Thermophysical properties and thermal resistance function of permeable asphalt concrete

为研究透水沥青混合料的热物性,基于热力学理论计算比较了透水沥青混合料和密级配沥青混合料的热导率、比热容、热扩散率等指标,并对透水沥青混合料的热物性指标与空隙率、含水率的关系展开分析;通过设计室内光照试验,测得相同的传热条件下两种材料表面和底部的温度变化。理论计算结果表明同密级配沥青混合料相比,透水沥青混合料的热导率降低约20%,热扩散率降低约10%;室内温度测试结果显示,透水沥青混合料试件表面较密级配沥青混合料试件温度低2～2.5℃,底部温度低3～3.5℃,说明透水沥青混合料具有热阻功能,对气温荷载变化的抵抗能力较强,验证了理论计算结果。

In order to research thermophysical properties of permeable asphalt concrete,the indexes such as thermal conductivity,specific heat capacity and thermal diffusivity was computational researched between permeable asphalt and density graded asphalt concrete based on thermodynamic theory,the relationships between thermophysical properties of permeable asphalt concrete with air void moisture content were analyzed;indoor irradiation experiment was designed for determination the temperature change of PAC AC specimens.Theoretical calculation results indicate that permeable asphalt concrete is reduced by 20% with thermal conductivity,10% with thermal diffusivity,which is compared with density graded asphalt concrete;indoor temperature measurement results indicate that compared with density graded asphalt the temperature is decreased by 2-2.5℃ in the surface and 3-3.5℃ in the bottom of permeable asphalt concrete specimen,shows that permeable asphalt has function of thermal resistance,has strong resistant ability for the temperature load variation.Theoretical calculation results were verified.