Abstract：In order to investigate the fatigue failure evolution of improved asphalts, the Dynamic Shear Rheometer (DSR) was used for the time scanning test on rock asphalt/SBS (RA/SBS) composite improved asphalt, rock asphalt/crumb rubber (RA/CR) composite improved asphalt, rock asphalt (RA) improved asphalt and SBS improved asphalt under stress-controlled and strain-controlled modes. Based on the appearance-based method and the theory of energy dissipation, the curves of various physical indexes varying with the cycles of loading were obtained. The fatigue behavior of improved asphalts was studied systematically by analyzing the curve variation rule, and the fatigue failure indexes (G*sinδ,TF,Nf50,Nfm,Nm,N2 and Np20) of improved asphalt were determined, so that the indexes can be employed to the fatigue performance and life evaluation of improved asphalts. The evaluation results of different fatigue failure indexes were comprehensively analyzed and objectively evaluated, so that the optimal fatigue failure criteria applicable to the study of improved asphalts can be determined. The research results showed that different fatigue failure indexes exhibit significant differences in the fatigue performance evaluation of improved asphalts. The fatigue life of improved asphalts in this study depends on loading control mode of time scanning test. Under the same loading mode, the ranking results of fatigue life of improved asphalts by applying various fatigue failure criteria were consistent. Understress-controlled mode, the best fatigue resistance can be attained under the condition of RA/SBS with 5% rock asphalt and 2% SBS, and under strain-controlled mode, the optimal fatigue resistance can be achieved under the condition of RA/CR with 5% rock asphalt and 18% rubber powder. The fatigue performance of improved asphalts can be significantly improved by reducing the content of rock asphalt and increasing the content of rubber powder in RA/CR. The fatigue failure indexes Nf50 and Nfm close to the state of complete fatigue failure of improved asphalts can be used as the fatigue failure criteria of improved asphalts investigated in this study according to the geometric position of fatigue failure indexes.
王淋 郭乃胜 温彦凯 李薇 尤占平. 几种改性沥青疲劳破坏评价指标及性能研究[J]. 土木工程学报, 2020, 53(1): 118-128.
Wang Lin Guo Naisheng Wen Yankai Li Wei You Zhanping . Study on fatigue damage evaluation indexes and #br#
properties of several improved asphalts. 土木工程学报, 2020, 53(1): 118-128.
