水泥基渗透结晶型防水材料对硫铝酸盐水泥固化土性能影响及机制分析

发布时间：2018-02-11 14:12

本文关键词： 固化土水泥基渗透结晶型防水材料(CCCW) 无侧限抗压强度水稳定性干湿循环微观结构　出处：《岩土力学》2016年02期 　论文类型：期刊论文

【摘要】：水泥土固化过程中Ca~(2+)浓度会随水化反应的进行而逐步降低,导致水泥颗粒未完全水化,固化土强度增长受限,而水泥基渗透结晶型防水材料(CCCW)中活性物质能催化未水化水泥颗粒反应。选择硫铝酸盐水泥(SAC)为胶凝材料、CCCW为添加剂,通过单掺与复掺的方式,结合X射线衍射(XRD)、电镜扫描(SEM)表征,分析了固化土的无侧限抗压强度、水稳定性、耐干湿循环性能及微观结构。结果表明,复掺16%混合料(4%CCCW+12%SAC)的固化土强度是同掺量下单掺SAC固化土强度的1.5倍,且比单掺20%SAC的固化土强度高1.41 MPa;复掺16%混合料(4%CCCW+12%SAC)的固化土泡水2~8 d软化系数平均达0.97,而同掺量下SAC固化土平均仅为0.73;单掺的固化土强度随干湿循环次数增加逐级降低,而复掺混合料的固化土强度呈波浪式发展;CCCW中活性物质能增加固化土中钙矾石生成量并修复微裂缝,钙矾石长径比显著增大,可直接连接两个甚至多个土颗粒,形成三维网状结构,显著提高结晶体的微观加筋、骨架及填充作用,改善SAC固化土强度、水稳定性及耐干湿循环性能。
[Abstract]:During cement-soil solidification, the concentration of Ca~(2) will gradually decrease with the hydration reaction, which leads to the incomplete hydration of cement particles, and the increase of strength of solidified soil is limited. However, the active substances in cement-based permeable crystalline waterproofing material can catalyze the reaction of unhydrated cement particles. Sulphoaluminate cement (SACW) is chosen as the cementing material and CCCW as additive. The unconfined compressive strength, water stability, dry-wet cycle resistance and microstructure of the solidified soil were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The strength of solidified soil mixed with 16% mixture (4CW12 / SAC) is 1.5 times as high as that of SAC mixed with the same amount of addition. The strength of solidified soil was 1.41 MPA higher than that of 20% SAC, and the softening coefficient of solidified soil mixed with 16% mixture (4CW12 SAC) reached 0.97 in 2 ~ 8 days, but the average value of SAC solidified soil was only 0.73 in the same amount, and the strength of single mixed soil decreased gradually with the increase of dry and wet cycles. However, the strength of the solidified soil mixed with the mixture is wave-like. The active substances in CCCW can increase the amount of ettringite and repair the micro-cracks in the solidified soil, and the aspect ratio of ettringite can be increased significantly, which can directly connect two or more soil particles. Three-dimensional reticular structure was formed, the microscopic reinforcement, skeleton and filling of the crystal were significantly improved, and the strength, water stability and dry-wet cycle resistance of SAC solidified soil were improved.
【作者单位】：后勤工程学院化学与材料工程系;
【基金】：后勤科研计划重点项目(No.BY211C016) 重庆市基础与前沿研究计划项目(No.cstc2015jcyj A3005)~~
【分类号】：TU521.3

【参考文献】