doi:10.16186/j.cnki.1673-9787.2023030028

Received:2023/03/11

Revised:2023/04/21

Published:2024/05/15

Multi-scale study on bending fatigue damage strength of asphalt mixture

LI Youyun1, WANG Bin1, GAO Yingli1, LYU Yan2

1.School of Traffic & Transportation Engineering，Changsha University of Science & Technology，Changsha  410114，Hunan，China 2.Jiangsu Zhongshe Group Co.，Ltd.，Wuxi  214000，Jiangsu，China

Abstract: Objectives To validate the effectiveness of multi-scale numerical simulation methods in predicting the variation of flexural strength parameters during the fatigue damage process of asphalt mixtures in semi-circular bending tests.   Methods Based on the multi-scale algorithm concept and the semi-circular bending test，a micro-structure analysis of asphalt mixture specimens is conducted to determine the distribution pattern of geometric characteristics of internal aggregate particles； on this basis， the asphalt mixture was divided into five micro-region scales， and finite element models （FEM） of the semi-circular bending specimens at these scales were constructed. The multi-scale iterative calculation was then used to predict the flexural strength of asphalt mixtures at different semi-circular bending fatigue damage levels of 0%， 20%， 50%， 65%， and 80%（N_f the fatigue life）. The flexural strength parameters of asphalt mixtures with different particle sizes obtained from indoor semi-circular bending tests were used as macroscopic verification experiments， and a comparative analysis was conducted with the flexural strength obtained from multi-scale algorithm numerical simulation experiments.   Results The results show that in the fatigue damage process of asphalt mixtures， the decay rate of flexural strength is relatively slow in the early stage， but enters a rapid decline phase in the middle and later stages， the decay patterns obtained from the multi-scale numerical simulation tests are consistent with those from indoor tests， with the absolute value of the relative error in flexural strength controlled within 8%.   Conclusions The multi-scale numerical simulation is effective in predicting the flexural strength parameters of asphalt mixtures during the fatigue process. This algorithm can provide a reference for similar practical engineering projects．  

Key words:asphalt mixture;semi-circlular bending test;microstructure;fatigue property;stiffness parameter;multi-scale prediction