早龄期混凝土路面板非线性温度场下温度应力的计算

给出了一种早龄期混凝土路面板非线性温度场下温度应力的解析计算方法。模型将路面板厚度方向的非线性温度分成平均温度、线性温度和非线性温度三个分项,每一分项温度引起应力分别计算,最终总应力为三部分应力的叠加。此外,由于徐变对温度应力发展具有很大影响,因此该文也对混凝土徐变对板内温度应力的影响进行了分析。模型预测结果表明:在非线性温度分布下,温度应力沿板厚也是非线性分布的,温度变化产生的最大温度应力可能出现在路面板厚度方向的任何高度上,这依赖于沿板厚方向的温度分布特征。混凝土徐变会显著的降低路面板内的温度应力。

CALCULATION OF THE THERMAL STRESSES IN CONCRETE PAVEMENTS AT EARLY AGES

An analytical solution of thermal stress in concrete pavement subjected to a nonlinear temperature distribution is presented.In the analytical model,the temperature distribution along the slab depth is divided into three components,an average temperature component,a linear temperature component and a nonlinear temperature component.The thermal stresses resulted by each temperature component are calculated separately.The total thermal stress is obtained by superimposing the three stress components together.In addition,the effect of concrete creep on the thermal stresses is taking into account in the calculation.The computing results of the model show that as a result of the nonlinear characteristic of the temperature distribution,the thermal stress is nonlinearly distributed along the slab depth.The maximum stress may occur at any location along the slab depth,which is governed by the sum of three stress components.Concrete creep significantly reduces the thermal stress.