水泥与碱激发材料协同固化氯盐渍土的机理研究

Mechanism Study of Chlorine Saline Soil Synergistically Solidified by Cement and Alkali-Activated Materials

摘要:

研究了水泥与碱激发矿渣/粉煤灰（AASF）复掺比例和龄期对固化氯盐渍土力学性能的影响及其固化机理.结果表明：当水泥与AASF按照最佳质量比11∶9掺加时，固化氯盐渍土各龄期的抗压强度均较纯水泥固化氯盐渍土高出50%左右；水泥与AASF的反应可以相互协同，所生成的水化硅铝酸钙和水化硅铝酸钠凝胶能够持续物理吸附游离Cl^-，有效减轻了Cl^-对水泥水化的抑制作用，同时水泥的水化进一步提高了AASF的反应速率和程度；水泥与AASF复掺固化氯盐渍土的胶凝性产物相较于纯水泥固化氯盐渍土明显增多，硬化体的结构也更加致密．

Abstract:

The effects of cement and alkali-activated slag/fly ash（AASF） composite mixing ratio and age on the mechanical properties of solidified chlorine saline soil were investigated. The solidification mechanism of cement-AASF for chlorine saline soil was also investigated. The results show that when the optimum mixing ratio of cement and AASF is 11∶9， the compressive strength of solidified chlorine saline soil at each age is about 50% higher than that of cement single curing. The reaction between cement and AASF can be synergistic， the generated hydrated calcium aluminosilicate and sodium silicate aluminate hydrate gels produce continuous physical adsorption for free Cl^-， which effectively reduces the inhibitory effect of Cl^- on cement hydration. At the same time， the hydration of cement further promotes the reaction rate and degree of AASF. Compared with pure cement solidified soil， the amount of cementitious products in this method is significantly increased and the structure of hardened soil is more compact.