循环硫化床粉煤灰固化土的试验研究

Experimental Study on Soil Solidifying Agent from Industrial Wastes

循环流化床粉煤灰(CFB灰)作为锅炉的主要固体废弃物,其资源化利用尚处于起步阶段。利用CFB灰的水化特性,制备以CFB灰为主、电石渣和脱硫石膏为辅、完全使用工业废渣的土体固化剂,提出CFB灰资源化利用的新方法。通过固化土室内试验,探究固化剂配比、养护龄期对固化土无侧限抗压强度的影响。结果表明:CFB灰活性高于普通粉煤灰;配比为CFB灰∶电石渣∶脱硫石膏=7.2∶1.8∶1,固化剂掺入量为10%时,固化土28天无侧限抗压强度可以达到2.12 MPa;固化土强度可以满足复合地基和止水帷幕中固化土天搅拌桩对于强度的要求。

Circulating fluidized bed fly ash （ CFB ash）, as emerging solid waste of combustion boilers, is in the initial stage of resource utilization yet. In virtue of hydration characteristics of CFB ash, soil solidifying agent is prepared by CFB ash mainly with the aid of carbide slag and desulfurization gypsum, which uses industrial wastes completely. Based on this, the paper proposed a new method for resource utilization of CFB ash; then through the indoor test on the solidified soil, studied the effect of the agent content and curing duration on the unconfined compressive strength of the solidified soil. The result shows that CFB ash has better pozzolanic activity than common fly ash; when the proportion of CFB ash： CS： FGDG is 7.2 ： 1.8 ： 1, and the solidifying agent content is 10 %, the unconfined compressive strength of solidified soil （28d） can reach 2. 12 MPa; and the strength can meet the requirement of mixing piles in composite foundation and waterproof curtain.