| Asphalt pavement rutting, upheaval and other diseases are mostly caused by the lack of the shear strength of asphalt mixture. At present, the test methods are complicated and instruments are expensive for application, which are used to test the shear strength of asphalt mixture. In this paper, a new test method for asphalt mixture rotary shear failure is conducted in-depth research, and the influence factors of failure strength are discussed.Firstly, it was believed that the inner stress of asphalt pavement structure under vertical and horizontal loads mostly distributes in road surface. The specimen’s stress and strain distribution under torsion were analyzed with material mechanics and engineering mechanics. And calculation formula of the stress and strain was deduced.Secondly, this paper introduced the test method and its test device for rotational shear asphalt mixture, and putted forward the test scheme. Single variant was used to control the test temperature, the free torsion length, the particle size and other basic material parameters,198groups of specimens were tested under different test conditions. The failure strength index such as the maximum shear stress, maximum shear strain, secant modulus, tangent modulus, maximum torque, etc were listed and analyzed by the test data.The damage index of specimen was calculated, and stress-strain diagram was draw according to the test data, the failure mode and type of rotary shear was analyzed by the failure picture. The correlation between rotary shear failure strength and test variables was researched by analyzing the test data under different test condition. It shows that the rotary shear strength index of specimen has a significant downward trend when the temperature rises and the free torsion length increases, particle size also has a great impact on its shear strength, but the size difference also causes the variation of asphalt aggregate ratio, void ratio and so on, which need further research. |
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