水泥基土壤固化剂固化土的微观结构特征

Microstructure Characteristics of Soil Stabilized with Cement-based Soil Stabilizer

采用扫描电镜和能谱分析测试手段,对水泥基土壤固化剂固化土的微观结构和固化剂的水化产物进行了研究.结果表明:水泥基土壤固化剂水化产物包括水化硅酸钙(C-S-H)凝胶、氢氧化钙、碳酸钙、三硫型水化硫铝酸钙(AFt)等物质,其中C-S-H凝胶、AFt是构成固化土强度的主体;六方棱柱状的AFt晶体和纤维状的C-S-H凝胶(Ⅰ)纵横交替搭接成网状结构,插入或填充于土颗粒孔隙之中;网络状或其他形状的C-S-H凝胶附着在土颗粒表面并将其包裹起来,或将相近的土颗粒黏结起来.水泥基土壤固化剂水化产物的填充、挤密、黏结等作用,使呈松散状态的土颗粒逐渐成为较致密的整体,从而改善了土体的工程技术性能.

Using the measurement methods of scanning electron microscope and energy spectrum, the microstructure characteristics of the soil stabilized with cement-based soil stabilizer and the hydration products were studied. The experimental results show that the hydration products include hydrated calcium silicate gel, calcium hydroxide, calcium carbonate, ettringite and so on. Hydrated calcium silicate gel and ettringite are principal components for the strength of stabilized soils. The hexagonal prism ettringite and fibrous hydrated calcium silicate gel become the reticulated structure to insert or fill in the pore between soil particle. The hydrated calcium silicate gel with network and other shapes have attached on the soil particle to enwrap it or connect the soil particle. The loose soil particle has gradually turned to the more compact monolith that improves the engineering characteristics of soil mass through the effect of fill and pack and cementation of hydration products of soil stabilizer.