多孔混凝土疲劳性能的研究

多孔混凝土作为路面的基层,和面层一起受到车辆荷载和温度的反复作用,结构设计中需考虑其疲劳性能。通过室内小梁弯拉疲劳试验,分析疲劳寿命试验数据的概率分布,得出多孔混凝土疲劳寿命服从双参数威布尔分布,以此建立了不同应力水平和等效应力水平下两种形式的疲劳方程;分析了疲劳寿命变异性的影响因素及减小变异性的相应措施,比较得出其疲劳性能优于半刚性基层材料。利用得出的疲劳方程,建立了以多孔混凝土作为水泥混凝土路面下面层荷载应力计算的疲劳应力系数,以及作为沥青路面基层时,进行层底弯拉应力验算的弯拉强度结构系数,可用于路面结构计算。

Study of fatigue property of porous concrete

As base course material, porous concrete withstands the repeated action of traffic and temperature,so the fatigue property should be considered in structure design. According to indoor flexural fatigue tests,authors analyzed the probability distribution of fatigue life,drew that the fatigue life of porous concrete obeys the two-parameter WEIBULL distribution, and built two types of fatigue equation under different stress level and equivalent stress level. Authors also analyzed the influencing factors of fatigue life and corresponding measures to reduce the variability, and got that the fatigue property of concrete is better than the semi-rigid base materials. At last, with the fatigue equation,authors built the fatigue stress coefficient which was used in the load stress calculation for porous concrete as undersurface of cement concrete pavement, and the structure coefficient of flexural tensile strength which was used in the flexural stress check for porous concrete as base of asphalt pavement.