Abstract: It is reported that cement concrete pavement occurs inchoate cracks at concrete slab bottom while shrinking,which is a defect.According to this,the basic principle of fracture mechanics is used and the relationship among crack depth at concrete slab bottom,loading,and stress strength factor is got by calculating.And then the expansion condition of pavement's crack is analyzed.Besides,fatigue equation is used to establish the relationship between load repetition and stable fracture tenacity descent,which explains that the basic cause of concrete pavement crack failure is that accumulation total damage resulting from fatigue loads leads to stable fracture tenacity descent.

Key words: cement concrete pavement, inchoate crack, stress strength factor, load repetition, stable fracture tenacity

摘要： 研究表明,水泥混凝土路面在凝固收缩过程中形成板底早期裂缝,产生缺陷。为此,采用了断裂力学的基本原理,通过计算得出路面板底裂缝深度、荷载大小和应力强度因子之间的关系,分析了路面裂缝扩展的条件。同时,利用疲劳方程建立了荷载作用次数与稳定断裂韧度下降之间的关系式,由此说明疲劳荷载作用下产生的累计损伤导致的稳定断裂韧度下降是路面开裂破坏的根本原因。

关键词: 水泥混凝土路面, 早期裂缝, 应力强度因子, 荷载作用次数, 稳定断裂韧度