防水抗裂功能层沥青混合料的配合比设计优化研究

在沥青路面半刚性基层和柔性面层之间设置防水抗裂功能层,可以有效缓解路面结构的应力集中现象,减少路表水的下渗,延缓反射裂缝的产生与扩展速度。确定此功能层的油石比在很大程度上影响了其具体的路用性能,采用体积设计法(CAVF)按照最紧密骨架结构设计的沥青混合料油石比为下限,以析漏试验的拐点作为油石比上限。在此范围内,再配合高温车辙试验和小梁弯拉试验来确定最佳油石比。

Optimization of Mix Proportion of Waterproof and Anti-crack Asphalt Mixture

Waterproof anti-cracking layer is laid between the semi-rigid base and flexible surface layer of an asphalt pavement to effectively alleviate the stress concentration of the pavement structure, reduce the surface water infiltration, and delay reflective cracks and expansion veloci- ty. The determination of the bitumie-aggregate ratio of the functional layer of asphalt has great influence on the road performance, so the lower limit of the bitumie-aggregate ratio of asphalt mixture should be designed with the volume design method （CAVF） according to the most com-pact framework structure and the upper limit should be determined according the inflection point of drain-down testing. Within this range,the optimal bitumie-aggregate ratio is decided with rut-ting testing and trabecular flexural testing.