水泥粉煤灰稳定废旧沥青混合料的收缩特性

Shrinkage Characteristics of Cement and Fly-ash Stabilized Waste Asphalt Mixture

为了合理利用废旧沥青混合料作为路面基层,研究其收缩特性,以水泥、粉煤灰稳定废旧沥青混合料为研究对象,通过正交试验设计和干燥收缩试验、温度收缩试验等方法,对其干燥收缩特性和温度收缩特性进行了试验研究.结果表明：干缩试验中,混合料的干缩应变与干缩系数均与暴露时间、失水率的增多成正比,水泥粉煤灰的比值在1∶3时混合料干缩应变与干缩系数最小.温缩试验中,混合料的温缩应变与温缩系数随着稳定剂剂量的增加而线性增长,并随着温度的降低而增大.同时采用正交试验设计方法中的极差分析和方差分析来确定因素水平变化,评价了影响混合料收缩特性4个因素的大小关系与显著性,分析表明：其收缩性能影响因素的排序为废旧沥青混合料含量〉1~3号粗集料〉粉煤灰含量〉水泥含量.

To use the waste asphalt mixture as road base rationally,the shrinkage characteristics of cement and fly-ash stabilized waste asphalt mixture is studied.Through the orthogonal experimental design and the drying shrinkage test,shrinkage test methods,the characteristics of drying shrinkage and temperature shrinkage are studied.The result shows that,in dry shrinkage test,the drying strain and coefficient increase with exposure time and water loss rate proportionally.When the ratio of cement to fly-ash is 1∶ 3,the shrinkage strain and shrinkage coefficient are minimum.During the temperature shrinkage test,the temperature shrinkage strain and shrinkage coefficient increase as the stabilizers increases linearly,and increases as the temperature decreases.By range analysis and variance analysis of the orthogonal experimental design method to determine the levels of factors to evaluate the shrinkage characteristics of mixture between the four factors.The analysis shows： the order of the shrinkage influence factors is the asphalt content 1# to 3# coarse aggregate fly ash content cement content.