基于力学性能和各向异性的排水性沥青磨耗层优化

Optimization of Wear Layer of Drainage Asphalt Based on Mechanical Properties and Anisotropy

为了研究排水性沥青混合料的各向异性和力学性能,对排水性沥青磨耗层进行优化,自行改装设计了车辙板渗水系数测试仪。该装置能够模拟实际雨水在路面中渗流的过程。研究对10种级配的沥青混合料进行了力学性能试验以及利用自行制作的渗水试验仪进行了渗水特性试验研究。研究结果表明,排水性沥青磨耗层的力学性能与排水性能呈负相关关系;对于同一最大公称粒径的不同级配沥青混合料,随着空隙率的增大,力学性能逐渐减小而排水性能增强;增大集料公称最大粒径,其力学性能和排水性能均有所增强。各向渗水差异性主要发生在横向渗水过程中,竖向渗水差异不大;增大排水性沥青混合料的空隙率和公称最大粒径可减小其各向异性。研究得出的最佳空隙率为18%~21%,坡度设置为1.2%~1.5%,可增强其排水性能。研究成果对排水功能性沥青路面的应用具有一定的理论与实用价值。

In order to study the anisotropy and mechanical properties of the drainage asphalt mixture,the drainage asphalt wearing course was optimized,and the seepage coefficient tester of rutting plate was designed.The device can simulate the seepage process of actual rainwater in the pavement.The mechanical properties of 10 kinds of graded asphalt mixtures were tested and the water permeability characteristics were studied by using the self-made water permeability tester.The results show that there is a negative correlation between the mechanical properties and the drainage performance of the drainage asphalt wearing course.For different graded asphalt mixtures with the same maximum nominal particle size,the mechanical properties gradually decrease and the drainage performance increases with the increase of the porosity.The mechanical properties and drainage properties are enhanced with the increase of the nominal maximum partical size of the aggregate.The results show that the anisotropy of asphalt mixture can be reduced by increasing the porosity and nominal maximum partical size of the asphalt mixture.The results show that the best void ratio is 18%~21%,and the slope setting is 1.2%~1.5%,which can enhance its drainage performance.The research results have certain theoretical and practical value for the application of drainage functional asphalt pavement.