矿渣电石渣基地聚合物固化土力学特性及微观机理分析

Mechanical Properties and Micro-mechanism of Polymer-Consolidated Soils on Slag and Electric Slag Bases

通过以矿渣和电石渣为碱激发原料、硅酸钠为碱激发剂形成的地聚合物(GCG)固化淤泥来实现工业固废以及废弃土的资源化利用.通过无侧限抗压强度(UCS)试验研究了固化剂组分、养护龄期和含水率对GCG固化土强度的影响规律,并通过扫描电镜试验(SEM)探究了其微观机理.试验结果表明:矿渣与电石渣的最佳配比为6.5∶3.5;当固化剂掺量大于10%时,固化土UCS值大幅提升,最大28 d UCS值为8.86 MPa;当碱激发剂掺量增加时,固化土UCS值先增大后减小,存在最优掺量7.5%;28 d固化土强度在7~14 d时增长速率较大,在其他龄期下增长速率较小;当初始含水率由30%增长至60%时,不同固化剂掺量下的固化土28 d UCS值降低了57.1%~92.5%;固化剂掺入7 d后在固化土体能产生更多的胶结物,使土体结构更加致密.

Industrial solid wastes and waste soils are utilized by forming geopolymer-cured sludge(GCG)using slag,calcium carbide slag as alkali-activated raw materials,and sodium silicate as the alkali-activating agent.The study investigated the effects of curing agent composition,curing time,and moisture content on the strength of GCGcured soil using the unconfined compressive strength(UCS)test,and explored the micro-mechanisms using scanning electron microscopy(SEM).The test results indicate that the optimal ratio of slag to calcium carbide slag is 6.5 to 3.5.With a curing agent dosage exceeding 10%,the UCS value of cured soil significantly increases,with a maximum 28 d UCS value of 8.86 MPa.As the alkali-activating agent dosage increases,the UCS value of cured soil initially rises and then declines,with an optimal dosage of 7.5%.The 28-day strength of cured soil exhibits higher growth rates between 7 to 14 d compared to other periods.Increasing initial water content from 30% to 60% reduces the 28 d UCS value of cured soil with different curing agent dosages by 57.1% to 92.5%.After 7 d,the curing agent promotes increased cementation in cured soil,densifying its structure.