عنوان مقاله [English]
نویسندگان [English]چکیده [English]
One of the important factors that could increase the life of asphalt pavement is proper implementation of asphalt layers. Binder and Topeka layers are some of the first layers related to the weight of vehicles which are connected by surface dressing. Passing of vehicles leads to create shear force in the adhesive area between the two layers, which in the absence of sufficient strength, this shear force causes damages such as shrinkage, longitudinal and transverse cracks and creates depressions on the pavement surface. This research has been performed as laboratory experiment and numerical modeling process. In the laboratory process, samples were constructed in Binder and Topeka layers and then contaminants such as crumb rubber, sand, wood chips and fibers were used in the surface dressing between the two layers to study the effect of each contaminant on inter-layer adhesion resistance. The samples were held by a jaw holder in order to fix the Binder layer, and then were put under the influence of vertical force of shear load machine situated in the Topeka area. In the numerical modeling process, the samples’ pavement was modeled for real conditions. In this process, the road surface was modeled and the passing of vehicles was simulated, and then the existence of the contaminants between the Binder and Topeka layers were evaluated. In the modeling process, by varying the thickness of Binder layer, velocity of passing vehicle and adhesion coefficient between the Binder and Topeka layers, the inter-layer adhesion force in the created situations was investigated. Based on the test results, among the investigated cases, the created sample with lower limit of gradation, which used crumb rubber as a contaminant between the Binder and Topeka layers, by increasing the resistance to 1.1 times more than the bitumen without contaminant, not only didn’t decrease the inter-layer resistance, but also had the greatest adhesion strength.