水泥固化温州污染土的力学性质和微观结构特性

Mechanical properties and microstructure characteristics of cement solidification pollution soil from Wenzhou

在不同水泥掺量和龄期条件下对NaCl、油脂、Pb(NO_3)_2污染的温州软土进行水泥固化处理后,土体的强度得到改善。为进一步得出水泥固化处理对于不同污染土的处理效果,对水泥固化稳定不同的污染土进行了无侧限抗压强度试验和微观结构研究。分析了不同污染物类型、污染物掺入量、水泥掺入量以及养护龄期对水泥固化污染土强度特性的影响以及不同污染物浓度下水泥固化土微观结构的差异。试验结果表明:NaCl在一定范围内促进了水泥固化土早期强度的提高;油脂使水泥固化土的强度明显降低,压缩性增大;Pb(NO_3)_2掺入到土体中后,水泥固化土的强度总体上略有降低,掺入量与强度之间大致呈线性关系。随着水泥掺入量及龄期的增加,水泥固化污染土的强度会有显著提高。扫描电镜(SEM)结果分析得出:由于污染物的作用,污染物浓度的增加使固化土中孔隙增多,结构变得疏松。

Under the condition of different cement content and curing time of NaCl,grease,Pb（NO3）2 pollution in Wenzhou soft soil cement solidification processing,the strength of the soil have been improved.In order to further obtain the treatment effect of different contaminated soil during cement solidification process,unconfined compressive strength tests and microstructure studies were conducted on different cement solidified contaminated soil.The effect of pollution type,pollution content,cement content,curing time on the cement solidified soil strength characteristics was analyzed.Furthermore,the difference of the microstructure of cement solidified soil with different pollutants concentration was alsoanalyzed.The results show that within a certain range,the NaCl concentration promotes cement solidification of the early strength;grease content makes the cement solidification soil strength reduce obviously and compressibility increase;after Pb（NO3）2 was dropped into the soil,the strength of the cement solidification is reduced in general.A linear relationship appears between the strength and admixing amount.The cement solidification soil strength enhances with the increase of cement content and curing time.Scanning electron microscopy（SEM）results indicate that the increase of contaminate leads to the rise of porosity and loose structure of the solidified soils.