多种固体废弃物基土壤固化剂的固化效果及机理研究

Study on solidified performances and mechanisms of several solid wasted based soil stabilizers

为了减少水泥的使用,提高固体废弃物的利用率,研究了3种固废基无机固化剂[SSC固化剂(75%矿粉+20%石膏+5%水泥)、SDG固化剂(60%矿粉+30%电石渣+10%石膏)、CDF固化剂(40%电石渣+30%粉煤灰+30%水泥)]对工程渣土的固化效果及无侧限抗压强度、水稳系数、吸水率、干湿循环等性能的影响。结果表明:固化剂加入后,固化土的最佳含水率增大,最大干密度减小;3种固化剂中,SDG固化强度最高,7、28 d无侧限抗压强度分别达到了4.96、5.42 MPa;SSC固化效果最差,尤其在早期,7 d无侧限抗压强度仅为2.16 MPa,同时其水稳系数仅为0.727;微观分析表明,SDG固化土相较于SSC及CDF固化土内部水化反应更完全,颗粒间更密实,结构更稳定。

In order to reduce the use of cement and improve the utilization of solid waste,the solidifying performances of three solid waste based inorganic stabilizers(SSC with 75% ground slag,20% gypsum and 5% cement,SDG with 60% ground slag,30% carbide slag and 10% gypsum,CDF with 40% carbide,30% fly ash and 30% cement) were investigated in this paper,mainly including the unconfined compressive strength,water stability coefficient,water absorption rate and resistance to drying-wetting cycles.The results show that the optimum moisture content increases and the maximum dry density decreases with the addition of soil stabilizers.Among the three stabilizers,the SDG-solidified soil owns the highest strength,and the unconfined compressive strength of 7 d and 28 d reached 4.96 MPa and 5.42 MPa,respectively.The SSC-solidified soil exhibits a poor solidifying performance,especially in the early stage,the strength of 7 d is only 2.16 MPa,and the coefficient of water stability is only 0.727.The microscopic analysis results show that compared with the SSC-solidified soil and the CDF-solidified soil,the SDG has a high hydration degree and the connection between the particles is more dense,thus,the structure is more stable.