连续配筋混凝土路面横向开裂的敏感性分析

Sensitivity analysis of transverse cracking for continuously reinforced concrete pavement

结合湖南省耒宜高速公路连续配筋混凝土路面(CRCP)结构,通过选取影响CRCP横向开裂的13个主要因素(包括板厚,混凝土的弹性模量、温缩系数、干缩应变、抗压强度和徐变系数,钢筋的弹性模量、温缩系数、直径和间距,以及地基摩阻系数、钢筋粘结强度和温降)的5种取值水平,采用考虑钢筋与混凝土之间粘结滑移及面板与基层之间摩阻滑移的交界面非线性性质和徐变作用的一维非线性分析法,由迭代计算同时得到CRCP的平均裂缝间距、平均裂缝宽度和最大钢筋应力,从而按相对比较的方法对各参数影响CRCP横向开裂的敏感性进行定量和定性分析。结果表明,控制CRCP横向开裂的主要措施有:选取适宜的钢筋等级、品种与混凝土标号,选取合理的钢筋间距和直径的配筋方式,并控制混凝土和钢筋的收缩性质。

5 kinds of Value level for 13 main factors influencing CRCP transverse cracking were selected from the structure of continuously reinforce concrete pavement （CRCP） in Lei- Yi （Leiyang to Yizhang） Expressway of Hunan Province. The factors are as follows： slab depth, elastic modulus, temperature shrinkage coefficient, drying shrinkage strain, compression strength and creep coefficient of concrete, elastic modulus, temperature shrinkage coefficient, diameter and spacing of longitudinal reinforcement, base friction coefficient, reinforcement bond strength and temperature differences. The average crack spacing, the average crack width and the maximum reinforcement stress were simultaneously calculated with the iterative algorithms according to the one - dimension nonlinear analyzing method considered the creep action and the nonlinear boundary properties, included in the bond - slip between reinforcement and concrete and the friction - slip between slab and base. So the sensitivities of CRCP transverse cracking influenced by each factor were analyzed in the quantitative and qualitative way with the relative comparing method. The results show that the main measures in controlling the CRCP transverse cracking are included in selecting the suitable grade and type of reinforcement and concrete grade, the reasonable reinforced way for spacing and diameter of reinforcement, and controlling the shrinkage properties of concrete and reinforcement.