半刚性基层沥青路面反射裂缝形成扩展机理与防治

半刚性基层沥青路面普遍存在反射裂缝．首先根据西尔斯和不里恩公式计算了半刚性基层中的温缩应力和干缩应力，指出它们是导致基层首先开裂的主要原因，在此基础上运用断裂力学观点阐述了沥青路面反射裂缝的两种开裂模式：剪切型，拉裂型．分别分析了行车荷载与温度荷载造成的不同破坏模式．最后针对影响裂缝形成和扩展的因素提出了3种防治措施，即增加面层厚度，改善基层的温干缩性质，设置应力吸收层．

Mechanism of Reflective Crack's Propagation in Semi-rigid Base AC Pavement and Preventing Strategies

Reflective crack widely exists in semi-rigid base AC pavement. In this paper, based on Hills, Brien formula, the contractive stress caused by low temperature and lost of water are calculated, the result shows that con- tractive stress in the base takes the main responsibility for reflective crack, furthermore, this paper has expatiated two types of cracking model: shearing, tearing. Different deteriorating models caused by axial loads and temperature load are analyzed. At last, three preventing and curing strategies (increasing the thickness of overlay, improving the properties of base materials, introducing SMAI layer) are forward according to the mechanism of reflective crack's propagation.