水泥稳定煤渣碎石基层的强度与损伤特性

为研究水泥稳定煤渣碎石作为路面基层材料的强度与损伤特性, 采用配方均匀试验方法, 获得了有约束条件下水泥稳定煤渣碎石基层的最优配比; 通过无侧限抗压试验与超声波测试对不同配比下的水泥稳定煤渣碎石的无侧限抗压强度与超声波波速进行了测试, 分析了超声波波速与无侧限抗压强度的关系; 根据超声波波速及试样的破坏过程, 对水泥稳定煤渣碎石的损伤变量进行了定义, 提出了损伤发展的控制阈值, 并建立了无侧限压缩条件下水泥稳定煤渣碎石基层填料的本构关系。研究结果表明: 水泥对基层材料的强度起到积极的影响, 而煤渣则会给材料强度带来负面影响; 水泥稳定煤渣碎石的最优配比为5∶35∶60 (水泥、煤渣、碎石的质量比), 其强度可达3.96 MPa, 可以作为路面基层填料使用; 随着材料抗压强度的增大, 超声波波速也有所增加, 但二者之间的规律性不强; 试件无侧限抗压试验过程可以分为压密阶段、弹性变形阶段、弹塑性变形阶段和破坏阶段, 利用超声波波速的变化可以将弹性变形阶段与弹塑性变形阶段进行区分; 根据超声波波速确定了水泥稳定煤渣碎石的损伤阈值为0.232, 材料可以带伤工作至损伤阈值处, 但不能超过损伤阈值。

Strength and damage characteristic of cement stabilized cinder macadam base

In order to study the strength and damage characteristics of cement stabilized cinder macadam as a pavement base material, the optimal proportion of cement stabilized cinder macadam base under constraint conditions was obtained using the formula uniform test method.The ultrasonic wave velocity and unconfined compression strength of cement stabilized cinder macadam were tested through unconfined compression test and ultrasonic wave velocity test for different proportions, and the relationship between them was analyzed.Based on the ultrasonic wave velocity and the failure process of the specimens, the damage variable of cement stabilized cinder macadam was defined, the control threshold of damage development was proposed, and the constitutive relationship of cement stabilized cinder macadam base filler under unconfined compression was established.Analysis result shows that cement has a positive effect on the strength of the base material, while cinder has a negative effect on the strength of the material.The optimum proportion of cement stabilized cindermacadam is 5∶35∶60 (the mass ratio of cement, cinder and macadam).The strength of cement stabilized cinder macadam can reach 3.96 MPa, and it can be used as pavement base filler.As the compression strength increases, the ultrasonic wave velocity also increases, but the regularity between them is not strong.The test process can be divided into the compaction stage, elastic deformation stage, elastic-plastic deformation stage, and failure stage.Elastic deformation stage and elastic-plastic deformation stage can be distinguished by the change of ultrasonic wave velocity.The damage threshold of cement stabilized cinder macadam is determined to be 0.232 based on the ultrasonic wave velocity.The material can work with damage up to the damage threshold but cannot exceed it.