氯盐环境下碱激发钢渣固化剂固化土的耐久性研究

Research on the durability performance of alkali activated steel slag solidifying agent in soil solidification under chlorine salt environment

对氯盐环境下碱激发钢渣固化剂固化淤泥土、粉质黏土、砂土耐久性开展了系统的室内试验研究及SEM微观分析,并在滨海深层搅拌桩工程中开展了现场试验。结果表明:固化剂固化淤泥土、粉质黏土、砂土均具有优异的强度及抗氯盐侵蚀耐久性,水泥固化粉质黏土、砂土的耐久性较为理想,但强度远低于固化剂固化土;水泥固化淤泥土强度、耐久性均远低于固化剂固化淤泥土。SEM结果显示,固化剂固化土微观表面致密且生成了大量的C-S-H凝胶和AFt,因此其具有更优的抗氯盐侵蚀性能;滨海环境固化剂深层搅拌桩28、180 d龄期强度约为水泥深层搅拌桩的1.8、2.1倍,固化剂相较于水泥更适用于滨海地区软土的固化。

This article conducted a systematic indoor experimental study and SEM microscopic analysis on the durability performance of alkali activated steel slag solidification agent for solidified silt,silty clay,and sandy soil under chlorine salt environment,and conducted on-site tests in the deep mixing pile engineering of coast.The results show that the solidifying agent has excellent strength and durability against chloride corrosion in solidified silt,silty clay,and sandy soil.Cement has ideal solidification durability for silty clay and sandy soil,but its solidification strength is much lower than that of the solidifying agent.Cement has much lower solidification strength and durability for silty soil than that of the solidifying agent;SEM results show that the solidified soil has a dense micro surface and generates a large amount of C-S-H gel and AFt,so it has better resistance to chloride erosion;The strength of deep mixing piles with solidifying agents in coastal environments at 28 and 180 days of age is about 1.8 and 2.1 times that of cement deep mixing piles.The solidifying agent is more suitable for the solidification of soft soil in coastal areas compared to cement.