Research On Interfacial Shearing Failure And Function Layer For Asphalt Pavement

Function layer for asphalt pavement is very important to the whole pavement structure. The main reason for shearing slippage between layers and interfacial shearing failure is due to the layer material deficiency and/or function layer setting incorrectly. This paper analyzed the recent research of the function layers and standard regulations of their materials. The shear stress distribution between the pavement layers is also analyzed with the flexible pavement structure layer theory based on the multi-layered system and the good functional layer is very important to the pavement. Then, the shear stress is calculated using the software BISAR 3.0 and the distribution of shear stress is obtained. The results show that the maximum shear stress is between the layers if the functional layers treated improperly under the vertical and horizontal load. Therefore, the functional material between layers is very essential.A new interlayer shearing tester was used to test the shear strain between layers and the interfacial shear was measured by twisting the multi-layers samples. The tester is exact, stable and easy to operate. The shear stress is also measured under the condition of different kinds of asphalt mixtures, different temperatures and different functional materials. Finally the optimum asphalt dosage of functional layers was obtained. The test results were testified at the experiment road at Jing-yu Expressway which is about 800m length with deferent functional materials and dosages. The shear stress was calculated with the pavement coring samples and the optimum asphalt dosage was determined. The conclusion is useful to the pavement design and construction.