新型复合激发锂渣基固化剂加固软土试验研究

摘要/Abstract

摘要： 为提高固体废弃物锂渣的利用率,以锂渣作为原材料,选择生石灰作为外添加剂,同时添加碳酸钙和氢氧化钠作为复合激发剂,利用碱激发技术研制一种新型软土固化剂材料。采用正交试验研究该新型复合激发锂渣基固化剂的固化配合比,并探究试验中各因素对固化土抗压强度的影响,同时结合XRD及SEM揭示固化剂与软土之间的固化机理及微观结构的演化规律。结果表明,固化剂的最佳配合比为锂渣掺量73%(质量分数)、生石灰掺量18%(质量分数)、复合激发剂掺量9%(质量分数)、碳酸钙与氢氧化钠质量比1∶1。该配合比下固化土7和28 d无侧限抗压强度分别为1.32和2.35 MPa,水稳定性系数分别为0.80和0.87。在生石灰与复合激发剂的协同作用下,固化土中水化硅铝酸钙(C-A-S-H)和水化硅铝酸钠(N-A-S-H)等胶凝物质显著增多,土体结构致密度提高强度及水稳定性提高。

关键词: 锂渣, 固化剂, 碱激发技术, 无侧限抗压强度, 水稳定性, 固化机理, 微观结构

Abstract: In order to improve the utilization rate of solid waste lithium slag, lithium slag was used as raw material, quick lime was selected as external additive, and calcium carbonate and sodium hydroxide were added as composite activators. A new type of soft soil curing agent material was developed by alkali excitation technology. The curing mix ratio of new composite excited lithium slag-based curing agent (CELS) was studied by orthogonal test, and the influences of various factors on the compressive strength of solidified soil were explored. At the same time, combined with XRD and SEM, the curing mechanism and microstructure evolution between curing agent and soft soil were revealed. The results show that the optimum mixture ratio of curing agent is 73% (mass fraction) of lithium slag, 18% (mass fraction) of lime, 9% (mass fraction) of composite activator, and the mass ratio of calcium carbonate to sodium hydroxide is 1∶1. Under this mix ratio, the unconfined compressive strength of solidified soil at 7 and 28 d is 1.32 and 2.35 MPa, respectively, and the water stability coefficient is 0.80 and 0.87, respectively. Under the synergistic effect of quicklime and composite activator, the cementitious materials such as calcium aluminosilicate hydrate (C-A-S-H) and sodium aluminosilicate hydrate (N-A-S-H) in solidified soil increase significantly, and the density of soil structure increases, thereby improving the strength and water stability of solidified soil.

Key words: lithium slag, curing agent, alkali-activated technology, unconfined compressive strength, water stability, solidified mechanism, microstructure

中图分类号:

X705
TU472

杨林, 杨建宇, 杨伟军. 新型复合激发锂渣基固化剂加固软土试验研究[J]. 硅酸盐通报, 2024, 43(7): 2556-2564.

YANG Lin, YANG Jianyu, YANG Weijun. Experimental Study on New Composite Excited Lithium Slag-Based Curing Agent for Reinforcing Soft Soil[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(7): 2556-2564.

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