一种自修复固化土的抗拉强度试验

固化土在道路工程上运用广泛,其抗压强度高但抗拉强度低,且易产生干缩裂缝导致强度降低.介绍一种具有强度自修复功能的固化剂,并对其开展抗拉(劈裂)强度试验研究.通过室内试验及电镜扫描试验发现,相较于传统的水泥固化土,添加自修复固化剂后,劈裂强度和水稳定性显著提升.养护3d和7d后破坏,水泥土和自修复固化土均具备一定的劈裂强度自修复能力,养护14 d后破坏,自修复效果大部分来源于自修复固化剂,且自修复强度随自修复固化剂掺量的增加而增加.水泥水化反应生成水化硅酸钙胶体(C-S-H),自修复固化剂中的水性聚合物经固化形成均匀的分子网络结构,两者相互搭接,形成了强度更高、孔隙率更小的交互空间结构.

Experimental study on tensile strength of a self-healing solidified soils

Solidified soil is widely used in road engineering, its compressive strength is high, but its tensile strength is low, and it is easy to produce dry shrinkage cracks, resulting in strength reduction.SIn this paper, a kind of curing agent with strength self repairing ability is introduced, and its tensile (splitting) strength test is carried out.SCompared with the traditional cement stabilized soil, the splitting strength and water stability of the soil were significantly improved after adding self-healing curing agent.SAfter curing for 3 days and 7 days, cement soil and self-healing solidified soil have certain splitting strength self-healing ability. After 14 days of curing, most of the self-healing effect comes from self-healing curing agent, and the self-healing strength increases with the increase of self-healing curing agent.SThe hydration reaction of cement generates hydrated calcium silicate colloid (C-S-H). The water-borne polymer in self-healing curing agent is solidified to form a uniform molecular network structure. The two overlap each other to form an interactive space structure with higher strength and smaller porosity.