Abstract：In order to obtain the modulus parameters of asphalt material in asphalt pavement structure and evaluate the structural performance of asphalt pavement reasonably, the study on the relationship between back-calculated modulus of asphalt pavement and the dynamic modulus of indoor asphalt mixture at the same temperature was conducted. Falling weight deflectometer (FWD) was used to test four asphalt pavement test roads with different structures, and the temperature sensors embedded in the pavement structure were used to collect the temperature synchronously. The modulus of asphalt layer was back calculated by test results. Asphalt mixture performance tester (AMPT) were applied to testing the dynamic modulus of asphalt material in test road, and the modulus values of asphalt mixture in FWD test at the same temperature were obtained according to the time-temperature equivalence principle. In consideration of the thickness of asphalt pavement structural layer, the equivalent modulus of dynamic modulus of asphalt mixture was calculated. FWD back-calculated modulus and the equivalent modulus of dynamic modulus of asphalt layer at the same temperature are analyzed and compared, and a regression model was established. The results show that the relationships between FWD back-calculated modulus of different pavement structures and indoor dynamic modulus are basically identical, the variation trend of the relationships is independent of the thickness of the asphalt layer. FWD back-calculated modulus of asphaltpavement has nonlinear relation with the modulus of asphalt mixture of indoor AMPT. When the modulus values are low, the back-calculated modulus of FWD is lower than that of indoor modulus. With the increase of modulus, the two modulus values are close around 10000MPa. With further increase of modulus, the back-calculated modulus of FWD increases faster than the indoor modulus, while the increase of indoor dynamic modulus tends to be mild.
