水泥土无侧限抗压强度表征参数研究

KEY PARAMETERS CONTROLLING UNCONFINED COMPRESSIVE STRENGTH OF SOIL-CEMENT MIXTURES

水泥土主要包括水泥加固土和水泥稳定土两大类。选用2种典型土样,分别配制高含水率的水泥加固土和低含水率的水泥稳定土,进行一系列的水泥土无侧限抗压强度试验,旨在分析水泥土的孔隙率、饱和度以及强度的变化规律,提出有效表征水泥土强度变化规律的参数。试验结果表明:水泥土孔隙率的大小与初始含水率、压实程度以及水泥水化产物生产量等相关;水泥土的饱和度随水泥掺入量或养护龄期的增加而降低;在常用的水泥掺入量范围(5%~20%)内,水泥土强度随水泥掺入量增加近似呈幂函数关系增大,水泥土强度与养护龄期的对数近似呈线性关系。基于试验结果,提出一个综合反映水泥掺入量、养护龄期以及孔隙率等因素对水泥土强度影响规律的综合表征参数,水泥加固土和水泥稳定土的强度均与综合表征参数呈幂函数关系。已有研究的试验数据也验证了提出的水泥土强度综合表征参数的有效性。

Soil-cement mixture includes cement treated soil and cement stabilized soil. A series of unconfined compressive strength tests of soil-cement mixture specimens after various curing periods were carried out on two typical soils samples with different water contents,in order to analyze the variation of porosity,saturation,and strength of soil-cement mixtures. The test results show that porosity of soil-cement mixtures is depended on the initial water content,the degree of compaction and hydration product output. Saturation decreases with the increase of cement content and curing time. There is a power function relationship between strength and cement content in term of the cement content between 5% and 20%. The strength of soil-cement mixtures grows linearly with the logarithm of curing time. A unique power function relationship well adapts unconfined compressive strength of soil-cement mixtures with a comprehensive parameter,which represents the effect of cement content,curing time and porosity. Test data from the literatures also demonstrate the effectiveness of the proposed comprehensive parameter to represent the strength characterization of soil-cement mixtures.