Evaluation of Self-healing Performance of Aging Asphalt Based on Dynamic Shear Rheometer
To evaluate the effect of aging on asphalt self-healing performance, repeated shear tests on 70# matrix asphalt and SBS modified asphalt aged through delayed rotating thin film oven test (RTFOT) are carried out under the stress control mode through dynamic shear rheological test (DSR). Intervals are drawn into the loading progress to make the self-healing phenomenon appear. The complex shear modulus of different ageing asphalt before and after healing is analyzed. The change ratio of complex shear modulus before and after healing (HI1) and the ratio of complex modulus before and after loading (HI2) are defined as selfhealing index of asphalt. These parameters are used to evaluate the self-healing property of asphalt. The results show that: the complex shear modulus of damaged asphalt can recover after self-healing thus the fatigue life is prolonged. The deeper the aging, the lower the self-healing ability of asphalt .The decrease rate of self-healing index with aging degree of 70# matrix asphalt is greater than that of SBS modified asphalt. Compared with HI2, it is more reasonable to evaluate the self-healing property by HI1.