【摘要】 为研究可再分散乳胶粉对水泥稳定碎石材料性能的影响，开展水泥胶砂试验及无侧限抗压强度、抗折强度、干缩、温缩路用性能试验，并通过X射线断层扫描(X-ray computed tomography, XCT)、扫描电子显微镜(scanning electron microscope, SEM)微观试验分析胶粉的作用机理。试验结果表明：胶粉应用于低剂量水泥基材料时，对强度和抗裂性具有显著的提升效果。考虑水泥稳定碎石的抗压强度、抗折强度及韧性，5%胶粉用量最优。5%胶粉水泥稳定碎石7 d无侧限抗压强度提高9.8%、抗折强度提高9.6%、弯曲韧性提升21.0%。掺入胶粉后，水泥稳定碎石的7、28 d干缩系数分别降低41.5%、34.0%,温缩系数降低17.1%,收缩性能得到显著改善。XCT图像分析显示，加入胶粉改变了水泥胶砂的孔隙特征，减少了大孔的数量，孔隙率和平均孔径是影响胶砂强度的主要因素。SEM结果显示胶粉可以增强水泥稳定碎石的界面粘结，优化其孔隙结构，并且与水泥水化产物联结形成弹性空间网络结构，是水泥稳定碎石韧性和收缩性能提升的主要原因。更多还原

【Abstract】 In order to study the effect of redispersible latex powder on the properties of cement stabilized crushed stone material, cement mortar test and unconfined compressive strength, flexural strength, dry shrinkage and warm shrinkage road performance tests were carried out, and the mechanism of latex powder was analyzed through X-ray computed tomography(XCT) and scanning electron microscope(SEM) microscopic tests. The test results show that when latex powder is applied to low-dose cement-based materials, it has a significant improvement effect on strength and crack resistance. Considering the compressive strength, flexural strength and toughness of cement stabilized crushed stone, the dosage of 5% latex powder is the best. After adding 5% latex powder, the 7 d unconfined compressive strength, flexural strength and flexural toughness of cement stabilized crushed stone increase by 9.8%, 9.6% and 21.0% respectively. After adding latex powder, the dry shrinkage coefficient of cement stabilized crushed stone at 7 d and 28 d decrease by 41.5% and 34.0% respectively, and the temperature shrinkage coefficient decreases by 17.1%, the shrinkage perfor-mance is significantly improved. XCT image analysis shows that the addition of latex powder changes the pore characteristics of cement mortar and reduces the number of macropores. Porosity and average pore diameter are the main factors affecting the strength of cement mortar. SEM results show that latex powder can enhance the interfacial bonding of cement stabilized crushed stone, optimize its pore structure, and connect with cement hydration products to form an elastic spatial network structure, which is the main reason for improving the toughness and shrinkage performance of cement stabilized crushed stone.更多还原