基于抗裂性能的水泥稳定碎石混合料级配研究

Study on Gradation of Cement Stabilized Macadam Mixtures Based on Crack Resistance

水泥稳定碎石基层抗裂性能较差,是引起沥青路面反射裂缝的根本原因。研究设计了6种不同级配水泥稳定碎石混合料,通过重型击实试验确定最佳含水率与最大干密度;分别测定各混合料试件的无侧限抗压强度、弯拉强度、抗压回弹模量及干缩系数,构建“抗裂指数”综合性评价指标,并分析级配对水泥稳定碎石混合料“抗裂指数”的影响。研究对提高水泥稳定碎石基层抗裂性能具有一定的指导意义。

The poor crack resistance of cement stabilized macadam base is the essential cause of reflection cracks in asphalt pavements.This paper designed six gradations of the cement stabilized macadam mixture,and the optimum water content and maximum dry density were determined by heavy compaction tests.The unconfined compressive strength,flexural strength,compressive resilience modulus,and dry shrinkage coefficient of each mixture specimen were measured.The comprehensive"crack resistance index"was established to evaluate the crack resistance of the cement stabilized macadam base,and the effect of the gradation on the"crack resistance index"of the cement stabilized macadam mixture was analyzed.This study has a certain guiding significance for improving the crack resistance of cement stabilized macadam bases.