基于工业副产物的高含水率固化土力学特性试验研究  

Experimental study on mechanical properties of high water content stabilized soil based on industrial by-products

作　　者：王腾 周佳锦 龚晓南[1] 俞建霖[1] WANG Teng;ZHOU Jia-jin;GONG Xiao-nan;YU Jian-lin(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,Zhejiang,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058

出　　处：《地基处理》2023年第5期361-368,共8页Journal of Ground Improvement

基　　金：国家自然科学基金项目(52108350)。

摘　　要：我国东部沿海地区广泛分布高含水率、高压缩性、低强度的软黏土,其工程特性较差。为提高土体强度,以普通硅酸盐水泥为基础,分别以矿粉、粉煤灰换掺部分水泥,同时掺入碱性激发剂石膏粉对软黏土进行固化处理,通过无侧限抗压强度试验对不同配比固化土的强度进行研究。试验结果表明,固化土无侧限抗压强度随龄期的增加而增长,3~7 d强度增长较快,7~28 d增长速率放缓;固化土强度随龄期的增长规律接近于规范中给出的经验值,固化土变形模量为其强度的45.9~114.7倍;养护时间达到28 d时,掺入比为10%水泥+10%矿粉+5%石膏的固化土强度最高,达到2700.0 kPa,15%水泥+5%粉煤灰+5%石膏的固化土强度最低,为743.9 kPa;石膏粉对矿粉的激发作用明显强于粉煤灰,其对土体强度的增长起主导作用,但过量的矿粉不利于土体后期强度的增长。结合原材料价格和固化土强度,5%水泥+15%矿粉+5%石膏最为经济合理,为本次试验的最优配比。Soft clay,characterized by high water content,high compressibility and low strength,is widely distributed in the eastern coastal areas of China,and its engineering properties are subpar.In order to improve the soil strength,based on ordinary Portland cement,mineral powder and fly ash were replaced with part of the cement,and the alkaline activator gypsum powder was added to stabilize the soft clay.The investigation involved unconfined compressive strength tests to evaluate the performance of the stabilized soil under different proportions.The test results show that the unconfined compressive strength of the stabilized soil increased with the curing time.Notably,the strength showed rapid improvement during the first 3-7 curing days,and the growth rate slowed down from 7-28 days,aligning with empirical observations.Furthermore,the deformation modulus of the stabilized soil was found to be 45.9-114.7 times its strength.At the 28-day curing mark,the mixture comprising 10%cement+10%mineral powder+5%gypsum exhibited the highest strength,reaching 2700.0 kPa.Conversely,the combination of 15%cement+5%fly ash+5%gypsum resulted in the lowest strength,measuring 743.9 kPa.Interestingly,the mineral powder was found to hinder the later-stage growth of soil strength.Based on the assessment of raw material costs and stabilized soil strength,the optimal and most economical ratio was identified as 5%cement+15%mineral powder+5%gypsum,as supported by the test results.This ratio holds significant promise for practical applications in soft clay stabilization and is recommended for engineering design and planning purposes.

关 键 词：固化土 无侧限抗压强度 高含水率 龄期 配比 

分 类 号：TU411[建筑科学—岩土工程]