冷再生基层沥青路面结构的断裂力学分析

Cracking Analysis on the Renewable Base-Course Asphalt Pavement Structure

目的从断裂力学角度研究水泥冷再生基层沥青路面结构的疲劳寿命,为水泥冷再生基层材料的合理使用提供依据.方法基于ABAQUS有限元计算软件,通过断裂力学方法对层底不同裂缝深度下水泥冷再生基层材料和常规半刚性基层材料的应力强度因子进行对比分析,找出残留层厚度和模量的变化对水泥冷再生基层应力强度因子的影响.结果由于半刚性基层材料的模量较大,所以在有裂缝的情况下,半刚性基层材料较冷再生材料容易开裂;增加残留层的模量对于降低水泥冷再生层的应力强度因子要优于增加残留层的厚度.结论残留层的厚度及模量对水泥冷再生材料的使用寿命有较大影响,推荐水泥冷再生基层沥青路面结构中残留层的厚度为10 cm,模量大于600 MPa以上.

The fatigue life of renewable base-course asphalt pavement from a point of view of fracture mechanics is studied, and a basic foundation for rational use of renewable base-course materials is presented. By using the ABAQUS finite element method and through the fracture mechanics, the stress intensity factor of renewable materials comparison with the conventional semi-rigid basing on the different length of the crack is analyzed. Furthermore, the stress intensity factor of renewable base-course on the influence of changing thickness and modulus of residual layer is studied. Under the circumstance of having crack, the semi-rigid materials are easily crazing, reducing the stress intensity factor of renewable base-course layer through increasing the modulus of residual layer have a great influence on the life of renewable materials on the structure of renewable base-course Asphalt Pavement. This paper recommends that the flfickness of residual layer is 10cm and modulus exceed 600MPa. The results of fatigue life of renewable base-course Asphalt Pavement which is shown in this paper have guidance significance for practical engineering.