湿陷性黄土改良用新型复合固化剂研究

Study on New Composite Curing Agent for Improving Collapsible Loess

为了有效提高黄土地区建筑结构的强度和稳定性,最大限度地降低黄土湿陷性对施工带来的不利影响,以甲基丙烯酸酯、丙烯酸和苯乙烯为主要合成原料,以SP-80作为乳化剂,通过乳液聚合法制备了一种适合湿陷性黄土改良用的新型复合固化剂FHG-1,并通过击实试验、无侧限抗压强度试验、抗剪强度试验、水稳定性试验和湿陷性试验对其综合性能进行了评价。结果表明:随着新型复合固化剂FHG-1加量的不断增大,湿陷性黄土的最佳含水量先降低后升高,最大干密度、无侧限抗压强度、抗剪强度和水稳定系数均逐渐增大,湿陷系数逐渐降低。当新型复合固化剂FHG-1的加量达到0.8%时,土样的最佳含水量最低可以达到19.1%,最大干密度为1.78 g·cm^(-3),28 d的无侧限抗压强度可以达到1.75 MPa,400 kPa垂直作用力下的抗剪强度可以达到1.54 MPa,水稳定系数可以达到95.3%,湿陷系数可以降低至-0.12,达到了较好的改良效果。

In order to effectively improve the strength and stability of building structures in the loess area,and minimize the adverse impact of loess collapsibility on construction,using methacrylate,acrylic acid and styrene as the main synthetic raw materials and SP-80 as the emulsifier,a new composite curing agent FHG-1 suitable for collapsible loess improvement was prepared by lotion polymerization.Its comprehensive performance was evaluated by compaction test,unconfined compressive strength test,shear strength test,water stability test and collapsibility test.The results showed that with the increasing of the new composite curing agent FHG-1 dosage,the optimum water content of collapsible loess decreased first and then increased,the maximum dry density,unconfined compressive strength,shear strength and water stability coefficient increased gradually,and the collapsibility coefficient decreased gradually.When the dosage of the new composite curing agent FHG-1 reached 0.8%,the minimum water content of the soil sample reached 19.1%,the maximum dry density was 1.78 g·cm^(-3),the unconfined compressive strength of 28 d reached 1.75MPa,the shear strength under the vertical force of 400 kPa reached 1.54 MPa,the water stability coefficient reached 95.3%,and the collapsibility coefficient was reduced to -0.12,achieving better improvement effect.