银川地区粉煤灰水泥土的力学特性试验研究

针对银川周边高矿化度湖泊相软土地基水泥土桩法处理问题,在软土天然含水量下,固定水泥掺量,应用搅拌法制备边长70.7 mm的立方体试件,标准条件养护,通过SANS万能材料试验机测定试件的强度和变形,通过扫描电子显微镜SEM进行微观结构分析,试验研究高掺量粉煤灰水泥土的应力-应变关系,强度随粉煤灰掺量、含水量、胶水比和龄期等因素变化的规律,并进行相关性分析,揭示作用机理。研究表明:在高掺粉煤灰条件下,水泥土的强度显著提高,且后期有很高的增长率,粉煤灰与水泥的最优掺量比约为3,主要作用机理为粉煤灰的水化效应和填充效应;水泥土的强度与粉煤灰掺量、胶水比、含水量之间近似为线性关系,其与胶水比的相关性最好。

RESEARCH ON MECHANICAL PROPERTIES OF FLY ASH CEMENT SOIL IN YINCHAN

On cement soil pile treatment of high mineralization lake deposits soft clay foundation in Yinchuan,cube test specimens with 70.7mm length of each side were prepared by mixing method under natural water content of soft soil and fixed cement content,strength and deformation of test specimens were determined by hydraulic universal material testing machine,microstructure of cement soil with fly ash content,water content,water cement ratio,cement ratio and age was analyzed by SEM.The σ-ε relationship and change in strength of high fly ash cement soil were studied,the rule and mechanism of strength were revealed.Under high fly ash condition,the strength of cement soil was increased remarkably.Later age strength growth rate was very high.The optimum ratio of fly ash and cement was about 3.Filling effect and hydration of fly ash were the main mechanism.The relationship between strength and fly ash content,cement water ratio,water content was approximately linear.The linear correlation between strength and cement water ratio was the best.