Elastic And Viscoelastic Analysis On Indirect Tension Test Of Asphalt Concrete

As a functional layer, the surface layer of asphalt pavement should meet the performances of skid resistance, wear resistance, noise reduction and quick water drainage, but its contribution to load bearing capability of pavement structure is insufficiently considered. In this paper, the surface layer of asphalt pavement was taken as an individual structural layer and its mechanical properties were studied by means of indirect tension test.Firstly, two-dimensional plane strain model was established to analyze the influence of the modulus of asphalt mixture, loading type on the indirect tension stress and the tendency that the indirect tension stress changed with them. Secondly, a new indirect tension test symmetrically cut on both sides of the specimen was put forward and analyzed. Through numerical simulation, formulas of splitting strength with four different model widths were fitted. Thirdly, for both cut and uncut specimen, the comparison of splitting stress between three-dimensional model and plane strain model was made. The splitting stress for three-dimensional model had different variation law from that for plane strain model. The variation of splitting stress with model width and the influence of boundary conditions on splitting stress were studied. Fourthly, the surface functional layer was considered as an individual structure layer and three-dimensional two-layer model was established. Under the conditions that the thicknesses of two layers in two-layer model changed together and that the thickness of one layer changed while the thickness of another layer fixed, the splitting stress of two structure layers and the interfacial stresses between two layers were obtained. Finally, the indirect tension test under the condition of viscoelasticity was simulated and the influences of temperature and loading rate on the splitting stress were analyzed, and the theoretical data is in good agreement with the measured data. This research provides a better understanding of the splitting test.