基于抗裂性能的水泥稳定类半刚性基层材料设计

Material Design of Cement Stabilized Semi-Rigid Base Course Based on Cracking Resistance

摘要: 为提高基层抵抗路基沉降变形开裂能力，本文对水泥稳定类半刚性基层的抗裂性能分析，采用断裂力学中应力强度因子的概念，并对其断裂能进行分析，通过无侧限抗压强度、弯拉强度指标分析，得到了抗裂性能最优的半刚性基层的级配类型及水泥用量。结果表明，采用骨架密实型的水泥稳定砂砾的抗裂性能最优；常规水泥剂量条件下，随着水泥剂量的增加，无侧限抗压强度、弯拉强度和断裂韧度增大，而断裂能则随之递减。综合分析认为，采用骨架密实型结构，4%的水泥用量的水泥稳定砂砾具有较高的抗裂性能。

Abstract: In this paper, in order to improve the resistance to deformation of subgrade settlement cracking ability, the concept of stress intensity factor in fracture mechanics is adopted. The unconfined compressive strength, flexural tensile strength, fracture toughness and fracture energy of the spe-cimens were analyzed. Through the multi index analysis, the gradation type and cement dosage of the semi-rigid base with the best crack resistance were obtained. The results show that the cement stabilized grit with skeleton dense type has the best crack resistance. Under the condition of con-ventional cement dosage, the unconfined compressive strength, bending tensile strength and fracture toughness increase with the increase of the cement dosage, but the fracture energy de-creases with it. Based on the comprehensive analysis, it is considered that cement stabilized gravel with a cement content of 4% has high crack resistance in the dense structure of the skeleton.