Simulation of top-down crack propagation in asphalt pavements

• Published in: Journal of Zhejiang University. A. Science 2010-03, Vol.11 (3), p.223-230
• Main Authors: Luo, Hui, Zhu, Hong-ping, Miao, Yu, Chen, Chuan-yao
• Format: Article
• Language: English
• Subjects: Civil Engineering; Classical and Continuum Physics; Engineering; Galerkin; Industrial Chemistry/Chemical Engineering; Mechanical Engineering; 厚度设计; 基础刚度; 应力强度因子; 沥青路面; 裂纹扩展; 覆盖层厚度
• ISSN: 1673-565X; 1862-1775
• DOI: 10.1631/jzus.A0900248

Top-down crack in asphalt pavements has been reported as a widespread mode of failure.A solid understanding of the mechanisms of crack growth is essential to predict pavement performance in the context of thickness design,as well as in the design and optimization of mixtures.Using the coupled element free Galerkin （EFG） and finite element （FE） method,top-down crack propagation in asphalt pavements is numerically simulated on the basis of fracture mechanics.A parametric study is conducted to isolate the effects of overlay thickness and stiffness,base thickness and stiffness on top-down crack propagation in asphalt pavements.The results show that longitudinal wheel loads are disadvantageous to top-down crack because it increases the compound stress intensity factor （SIF） at the tip of top-down crack and shortens the crack path,and thus the fatigue life descends.The SIF experiences a process ＂sharply ascending—slowly descending—slowly ascending—sharply ascending again＂ with the crack propagating.The thicker the overlay or the base,the lower the SIF; the greater the overlay stiffness,the higher the SIF.The crack path is hardly affected by stiffness of the overlay and base.