Fatigue Damage Evolution and Life Prediction Method of Asphalt Modified With High Content of Rubber Powder

Description

Fatigue Damage Evolution and Life Prediction Method of Asphalt Modified With High Content of Rubber Powder

Guoqing Wang, Dongwei Cao, Lusheng Qin, Shizhou Huang, Chao Wang

ABSTRACT

The application of waste rubber powder in asphalt modification technology has not only improve its road performance, but also bring significant economic and environmental benefits. In this paper, the fatigues performance of asphalt modified with high content of rubber powder (exceeding 30%) were investigated and compared according to rheological testing results with those with low content of ordinary rubber powder. The frequency sweep test, linear amplitude sweep test and time sweep test of matrix asphalt and rubber powder modified asphalt with different content were carried out by dynamic shear rheometer. Based on the dynamic mechanical response analysis of different loading and test conditions, the damage evolution process of high content rubber powder modified asphalt were systematically analyzed, and the life prediction method of high content rubber powder modified asphalt was established. The results show that the addition of high content rubber powder changes the fatigue crack length evolution law of matrix asphalt. Besides that, in the time sweep test, the high content rubber powder modified asphalt improves the anti-fatigue crack propagation ability as compared to those of original rubber asphalt. Its excellent fatigue performance was mainly shown in the fatigue crack propagation stage instead of the fatigue crack initiation stage. In order to establish the fatigue performance prediction method of asphalt modified with high content of rubber powder, three linear amplitude sweep tests with different loading rates and time sweep test with at least one strain level are needed as the input parameters of the model. The theoretical analysis results show that the fatigue life prediction model based on damage mechanics can predict and simulate the fatigue performance of asphalt modified with high content of rubber powder relatively accurately.