公路水泥混凝土的粘弹性特征研究

为研究适用于公路路面的水泥混凝土材料粘弹性特征,通过室内制备道路水泥混凝土试件,采用控制位移法进行一次加载、循环加载试验,分别测试了C30水泥混凝土试件分别在0.1、0.3、0.5 mm·min~(-13)种加载速率下的σ-ε曲线。通过对3种加载速率下的σ-ε曲线变化规律并采用割线模量E_s表征水泥混凝土的粘弹性。研究结果表明:水泥混凝土试件σ≤0.8σ_(max)时,σ-ε曲线近似线性增长,该范围可认为是水泥混凝土的弹性工作阶段;当σ≥0.8σ_(max)时,试件出现出较大的粘性变形特征,当应力超出屈服应力后发生脆性破坏。加载速率的不同会影响σ-ε曲线的弹性模量E_c和最大破坏应力σ_(max);E_c随着加载速率的增大而减小,σ_(max)随着加载速率v的增大而增大。

Research of viscoelasticity of cement concrete used in pavement

To study the viscoelastic characteristics of cement concrete pavement,the C30 concrete samples were prepared tested of σ-ε curves in the loading rates of 0.1,0.3 and 0.5 mm · min-1,respectively.The samples were tested with single loading mode and repeat loading mode,separately,under the condition of load displacement control.The change rules of σ-ε curves were simulated and the viscoelastic characteristics of cement concrete were investigated by using the secant modulus Es.The result shows that the σ-ε curves increase linearly in general under the condition of σ≯0.8σmax while the samples can be considered as elastomer material.The σ-ε curves increase non-linearly under the condition of σ≥0.8σmax while the samples can be considered as a brittle material.The loading rate can affect the secant modulus Es and the ultimate failure stress limit σmax.As the loading rate increases,the ultimate failure stress σmax increases while the secant modulus E,decreases.