基于控制裂缝和车辙的半刚性基层沥青路面力学行为分析

Mechanical Behavior Analysis of Semi-rigid Asphalt Pavement Based on the Crack and Rutting Control

针对目前重载车辆、高性能材料和大厚度结构层的采用，结合半刚性基层沥青路面在使用过程中出现的裂缝和车辙，通过分析不同荷载情况下半刚性基层和沥青面层在改变厚度和模量时的路面结构力学行为，研究路表弯沉、层底拉应力、拉应变和剪应力、剪应变的变化，提出了可以减少路面裂缝和车辙的半刚性基层和沥青面层的厚度和模量范围，改善了路面结构层受力，增强半刚性基层在高等级路面结构中的适应性。分析结果表明：控制裂缝为目的时，沥青面层厚度宜选用17～24cm，半刚性基层厚度宜选用35-50cm；沥青面层模量不宜大于2500MPa，半刚性基层模量宜在1400-2500MPa；控制车辙为目的时，沥青面层厚度宜选择16-25cm，模量宜为1800-3000MPa，半刚性基层模量宜为1600-3000MPa。

Adopting heavy vehicle, high performance materials and large thickness structure layer, combined with the growing crack and rutting, the changes of deflection on the surface, tensile stress, tensile strain, shear stress and shear strain were analyzed under the different loads, thickness and modulus. Then the range of thickness and modulus of semirigid base and asphalt pavement was proposed. It improves the force of structure and enhances the applicability of semirigid base in the high grade pavement structure. The experimental results show that if the purpose is to control crack, the thickness of semi-rigid base and asphalt pavement is 35-50 cm and 17424 cm respectively, asphalt pavement modulus is less than 2 500 MPa, and semi-rigid base modulus is in the range of 1 400-2 500 MPa. If the purpose is to control rutting, the thickness of asphalt pavement is 16-25 cm, the modulus is in the range of 1 800-3 000 MPa, and the semi-rig- id base modulus is in the range of 1 600-3 000 MPa.