عنوان مقاله [English]
Asphaltic concrete has been used as a waterproofing core for embankment dams since 1948. Worldwide, the large majority of the embankment dam central core is made of clay. However, as clay is increasingly difficult to find at new construction sites, asphalt concrete has been used as a replacement core material. Core made of clay has some further disadvantages, such as; low shear strength, compressibility, long construction time, requiring higher amounts of material, and accurate controls during construction, etc. The advantages of using asphalt concrete are; less sensitivity to weather conditions, less width of core, the healing behavior of bitumen and high shear strength etc. In this application, granular materials are used around the asphaltic concrete as a filter, which creates complicated behavior at the interface and which needs to be researched by experiment and modeling. This paper describes the experimental work and the results of investigating the mechanical behavior of the interface between aggregates and asphaltic concrete. A small scale shear strength test has been used in this study, in which the hear urface s onsidered as the interface. The effect of bitumen penetration grade, moisture, density and angularity of aggregates on the shear strength parameters at different levels of vertical stresses and constant shear rate was studied. Asphalt concrete specimens were cut in square shapes (10ش10ش2.5cm) from cylindrical specimen compacted by a modified marshal compaction method. The results show that the shear strength parameters increase with increasing the density and vertical stress level. It is also shown that the shear parameters decrease with increasing moisture content in the interface. The penetration grade of bitumen does not have a significant effect on the parameters. It is also demonstrated that the ratio of interaction between the aggregate and asphalt concrete decreases in a certain range of variation.