复杂应力条件下水泥沥青砂浆徐变特性试验研究

Test Study of Creep Characteristics of Cement and Asphalt Mortar under Complex Stress

为探明水泥沥青砂浆的粘弹力学特性,研究了不同应力条件下和不同配比水泥沥青砂浆的徐变特性。结果表明:随着围压的增大,水泥沥青砂浆的徐变变形量逐渐减小,相应的瞬时弹性变形、粘弹性变形和粘性流动变形都有减小趋势,在较高围压情况下,产生一定的固结效应;徐变变形量随着A/C的增加而增大,围压越小,徐变变形对于A/C的敏感性越强烈,通过分析可知,A/C越小,水泥沥青砂浆胶结硬化后的无机刚性骨架含量越多,其抵抗变形能力越强。利用遗传徐变理论建立了水泥沥青砂浆徐变模型的积分形式,结合常用的三种徐变核推导了水泥沥青砂浆的三种徐变模型方程,采用MATLAB软件结合试验数据进行了模型方程参数求解,通过曲线拟合对三种模型在不同试验条件下的适用性进行了评价,以期实现对水泥沥青砂浆长期力学变形行为的预测。研究结果可为水泥沥青砂浆的粘弹力学特性理论研究和实际工程耐久性预测提供一定参考。

In order to investigate the visco-elastic mechanical properties of the cement and asphalt mortar, the creep characteristics of cement and asphalt mortar are studied under different stresses and ratioes. The results show the creep deformation of cement and asphalt mortar de- creases gradually with the increase of confining pressures,with the corresponding instantaneous elastic deformation, visco-elastic deformation and visco-flowing deformation all having the trend of decrease, and cement-emulsified asphalt mortar showing some consolidation effect in higher confining pressure;creep deformation increases with the increase of A/C. the smaller the confining pressure is, the more strongly the sensitivity of the deformation with A/C is. The analysis shows that the smaller A/C is, the more the content of inorganic rigid skeleton of ce- ment and asphalt mortar after cement hardening is, whose ability that resists deformation is stronger. The integral form of creep model of ee- ment and asphalt mortar is established using the genetic creep theory. Three models＇ equations of mortar are derived through combining With three commonly creep nuclears. Using MATLAB software and combining with test data, the parameters of the models＇ equations are solved. By curve fitting, the application of three models under different experimental conditions is evaluated, in order to get the prediction of the long- term mechanical deformation behavior of cement and asphalt mortar. The study results would provide reference for the theoretical research of visco-elastic mechanical properties of cement-emulsified asphalt mortar and the durability prediction of practical engineering.