矿渣和粉煤灰固化南沙软土试验研究

摘要

Based on the addition of ordinary Portland cement ,soft soil reinforced by slag or fly ash in Nansha (China ) was studied .The effects of slag or fly ash ratio and curing period on the internal fraction angle ,cohesion and the uncon-fined compressive strength (UCS ) of the reinforced soil were researched .Scanning electron microscope (SEM ) observa-tion and x-ray diffraction technique (XRD ) were conducted to study different microstructure characteristics and the min-eral composition of different reinforced soil samples .The results showed that the replacement effect of slag was very obvi-ous and its ability of solidifying Nansha soft soil was better than that of cement ,and that the strength of soil reinforced by slag increased faster in the late curing period .On the contrary ,the replacement effect of fly ash was ineffective and its a-bility of solidifying soft soil was much weaker than that of slag .%以普通硅酸盐水泥为基础，分别以矿渣、粉煤灰换掺水泥对广州南沙软土进行固化处理，得出了固化土体的内摩擦角、黏聚力、无侧限抗压强度随各种固化剂掺入量及龄期的变化关系。通过电子显微镜观测（SEM ）和X射线衍射技术（XRD ）研究了不同固化土样的微观结构特征和土样的矿物组成。研究表明：在一定换掺量下，矿渣对水泥的换掺效果明显，其对于南沙软土的固化能力优于水泥，而且固化土后期强度增长速率较快；相反，粉煤灰对水泥的换掺效果却不佳，其固化软土的能力比矿渣弱得多。