Matching Relationships for Mechanical Parameters of Asphalt Pavement Materials Considering Difference in Tension and Compression

In view of the non-uniqueness of modulus selection and the mismatch among the values of various mechanical parameters of the same material in the current asphalt pavement design, typical pavement materials, asphalt mixture (AC), and cement stabilized macadam (CSM) were selected to perform unconfined compressive, direct tensile, bending, and splitting tensile tests. Then, the quantitative matching relationships among the mechanical parameters were established considering the velocity dependence and the different properties of tension and compression. Moreover, the superiority–inferiority of the four test methods was also evaluated by analyzing the stability and change law of test data and the specimens force characteristics. The results show that the difference in tension and compression of strength and modulus was the inherent attribute of the materials, which leads to the non-uniqueness of the mechanical parameters. The unconfined compressive and direct tensile tests are suitable methods to obtain mechanical parameters of pavement materials. The ratio of the direct tensile strength (modulus) to unconfined compressive strength (modulus) of AC decreases (increases) with the loading rate, while those of CSM shows an opposite regular pattern, and these above ratios of the two pavement materials tend to be a fixed value at higher loading rates. This research can provide a reference for the scientific selection and proper value of mechanical parameters in asphalt pavement design.