水泥改性聚乙烯醇固化轻质土的强度特性

Strength Characteristics of Lightweight Soil Amended by Cement-Modified Poly(vinyl alcohol)

为改善水泥固化轻质土存在的不足,采用水泥-改性聚乙烯醇(SH)对轻质土进行固化.分析探讨了水泥-SH固化轻质土的受压破坏方式、应力-应变曲线类型以及龄期、养护环境、SH掺量、土质成分对水泥-SH固化轻质土无侧限抗压强度的影响.结果表明:水泥-SH固化轻质土受压破坏没有出现明显的破裂面,且破坏应变较大,有较高的残余强度;室温养护下水泥-SH固化轻质土的无侧限抗压强度显著高于恒温恒湿养护;SH固化剂显著提高水泥固化轻质土无侧限抗压强度的最低掺量为4.5%(质量比);SH固化剂可以减小土质成分对水泥固化轻质土无侧限抗压强度的影响.

In order to amend the solidification of lightweight soil by cement,a new polymer binding material,i.e.modified poly（vinyl alcohol） known as SH was added to cement to solidify the lightweight soil.The investigation includes failure types and stress-strain curves of cement-SH amended lightweight soils subjected to unconfined compressive（UC） tests,the effects of curing age and condition,SH use level,and soil types on the UC strength of cement-SH amended lightweight soils.Test results indicate that the cement-SH amended lightweight soils show no clear shear plane,but significant strain at peak shear strength and relatively high residual strength when exposed to UC tests.The UC strength of cement-SH amended lightweight soil subjected to air curing is greater than that subjected to steam curing.A minimum SH use level of 4.5%（by mass） is suggested to enhance the UC strength of cement amended lightweight soil.SH solidifier mitigates the influence of soil types on UC strength of cement amended lightweight soil.