干湿循环作用下路面水泥混凝土的单轴压缩试验研究

Experimental study on uniaxial compression of pavement Cement concrete under wet⁃dry cycle

文章以辽宁某在建公路为案例,对该项目路面水泥混凝土进行不同干湿循环,不同加载速率下的单轴压缩试验,以此来揭示干湿循环和加载速率对路面混凝土物理力学性质的劣化机理。结果表明:干湿循环作用对混凝土具有明显的劣化作用,干湿循环次数越多,混凝土的峰值强度,弹性模量越小,峰值应变越大,且三者的变化幅度随干湿循环次数逐渐递增;干湿循环后混凝土的峰值强度和峰值应变具有明显的加载速率效应,二者与加载速率之间满足线性递增函数关系,相关系数均在0.9以上,而弹性模量随加载速率的增大并未表现出明显的规律性,分析拟合参数可知,随着干湿循环次数的增多,试样的加载速率效应逐渐增强。

Taking a highway under construction in Liaoning Province as an example,the uniaxial compression tests under different dry⁃wet cycles and different loading rates were carried out on the pavement cement concrete of the project,so as to reveal the deterioration mechanism of the physical and mechanical properties of pavement concrete caused by the dry⁃wet cycle and loading rate.The results showed that the dry⁃wet cycle had obvious deterioration effect on the concrete,and the elastic modulus was smaller with number of dry⁃wet cycles increased,while the peak strain was greater.The change range of the three parameters also gradually increased with the number of dry⁃wet cycles.After the dry⁃wet cycle,the peak strength and peak strain of concrete showed obvious loading rate effect,and both of them showed linear increasing function with loading rate.The correlation coefficient was above 0.9.However,the elastic modulus increased with the loading rate.According to the analysis of fitting parameters,the effect of loading rate increased with the increase of dry⁃wet cycles.