热阻沥青混合料研究进展

Research progress of thermal resistance asphalt mixture

为进一步评价热阻沥青混合料路用性能及阻热降温功效,系统梳理了热阻沥青路面研究成果,明确了路用热阻集料常用种类及其关键技术指标,评价了其基本性能;基于热阻沥青混合料路用性能研究调查结果,采用数理统计分析方法,确定了热阻沥青混合料常用热阻集料使用粒径及应用方式,评价了热阻沥青混合料路用性能;基于热阻沥青混合料降温功效调查结果,梳理了其降温测试方式,分析了热阻沥青混合料阻热降温机理,对比评价了热阻沥青混合料降温功效。研究结果表明:路用热阻集料主要包括铝矾石类、陶制品、膨胀蛭石及多孔玄武岩;路用热阻集料导热系数均较小,但力学特性普遍较差;热阻沥青混合料中热阻集料常用应用方式主要包括等体积替换普通粗集料或细集料、层间设置热阻黏封层、路表加铺热阻薄层;相比普通沥青混合料,热阻沥青混合料路用性能变化较明显,其中陶制品类和铝矾石类热阻沥青混合料高温稳定性平均下降10%~15%左右,多孔玄武岩和膨胀蛭石类热阻沥青混合料高温稳定性有上升趋势,而热阻沥青混合料的低温性能并无明显变化,但其水稳定性下降较显著;热阻沥青混合料中热阻集料替换普通集料方式应用时,试件5 cm厚度处降温幅度达4℃~7℃,其中铝矾石类降温效果最为显著,达6.2℃;陶制品虽能有效阻隔热量在沥青混合料中的传递,但会使热量在试件表层蓄积,导致试件表面温度升高。

To further evaluate the pavement performance and heat-resistance and cooling effects of thermal-resistant asphalt mixture,the current research results on thermal-resistant asphalt pavements were sorted out systematically,the common types and key technical indicators of road thermal-resistant aggregates were defined,and the basic performance of road thermal-resistant aggregates was evaluated.The investigation results were based on the pavement performance of thermal-resistant asphalt mixture.Mathematical statistical analysis was used to determine the particle size and application mode of thermal-resistant aggregates commonly used in thermal-resistant asphalt mixture,and the pavement performance of the thermal-resistant asphalt mixture was evaluated.Based on investigation results of the cooling effect of thermal resistance asphalt mixture,the cooling test methods of thermal resistance asphalt mixture were carded,the thermal blocking mechanism of thermal resistance asphalt mixture were analyzed and the cooling efficiency of thermal resistance asphalt mixture were evaluated comparatively.The results show that road thermal-resistant aggregates mainly include bauxite,ceramics,expanded vermiculite and porous basalt.The thermal conductivity of road thermal-resistant aggregates are low,but their mechanical properties are generally poor.The common application modes of thermal-resistant aggregates in thermal-resistant asphalt mixture mainly include equal volume replacement of common coarse or fine aggregates,setting the thermal-resistant adhesive seal layer between layers,and paving the thermal-resistant thin layer on the road surface.Compared with ordinary asphalt mixture,the pavement performance of the thermal-resistant asphalt mixture has obvious differences.Among them,the high-temperature stability of ceramics and bauxite thermal resistance asphalt mixture decrease by about 10%to 15%on average.The high-temperature stability of porous basalt and expanded vermiculite in thermal-resistant asphalt mixtures tend to increase.However,the low-temperature performance of thermal-resistant asphalt mixture do not change significantly,although its water stability decrease significantly.When thermal-resistant aggregates are used in the thermal-resistant asphalt mixture instead of ordinary aggregates,the temperature drop of the specimen with thickness of 5 cm ranged from 4℃to 7℃.Bauxite has the most significant cooling effect,reaching 6.2℃.Ceramics can effectively prevent heat transfer in the asphalt mixture,but will accumulate heat on the surface of the specimen,resulting in increased surface temperature.4 tabs,8 figs,34 refs.