贫混凝土基层疲劳特性研究

贫混凝土用于路面基层时,由于受到荷载应力和温度应力的反复作用,需研究其疲劳特性.通过分析室内小梁弯拉疲劳试验结果,得出贫混凝土的疲劳寿命服从双参数威布尔分布,据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.通过对比,得出贫混凝土的疲劳性能优于其他常用半刚性基层材料.利用得出的疲劳方程,建立贫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.

Study on Fatigue Property of Lean Concrete Base

Fatigue property of lean concrete should be studied when the material is set as base course since it withstands the repeated actions of load stress and temperature stress.By analyzing the indoor flexural fatigue tests of small beams,the paper Concludes that the fatigue life of lean concrete follows the two-parameter Weibull distribution,and establishes two types of fatigue equation under different stress level and equivalent stress level.The paper also Concludes that the fatigue property of lean concrete is better than the semi-rigid base materials.Lastly,with the fatigue equation,the paper establishes the fatigue stress coefficient which is used in the load stress calculation for lean concrete as undersurface of cement concrete pavement,and the structure coefficient of flexural tensile strength which is used in the flexural stress check for lean concrete as base of asphalt pavement.