电石渣-火山灰质胶凝材料固化盐渍土试验研究

以电石渣、粉煤灰和碱激发剂作为原材料制备一种盐渍土固化剂,采用正交试验方法研究各因素对固化盐渍土击实性能和抗压强度的影响,并探索电石渣-火山灰质胶凝体系固化盐渍土的固化机理和水化产物。结果表明:各因素对固化盐渍土抗压强度的影响顺序为:碱激发剂>胶凝材料掺量>m(电石渣)∶m(粉煤灰);固化盐渍土养护7 d抗压强度和水稳定性满足实际工程中对固化盐渍土强度的需求;在电石渣和碱激发剂双重激发下粉煤灰发生火山灰反应,反应产物以水化硅酸钙凝胶、钙矾石和二水石膏为主。当养护龄期为360 d时,试件内未发现明显的Ca(OH)2存留,说明固化土试件养护360 d时,火山灰反应基本完成。

Experimental study on solidified saline soil with calcium carbide slag and volcanic ash cementitious materials

A salinized soil curing agent was prepared from calcium carbide slag,fly ash and alkali activator,and the effects of different factors on compaction performance and compressive strength of solidified saline soil were analyzed by orthogonal test,finally,the curing mechanism and hydration products of solidified saline soil in calcium carbide slag-volcanic ash cementitious system was explored.The results showed that the influence of various factors on the compressive strength of solidified saline soil was ranked as the alkali initiator,the content of cementitious materials and the ratio of calcium carbide slag to fly ash;the compressive strength and water stability of curing saline soil for 7 d meet the demand of curing saline soil strength in practical engineering;Under the dual excitation of calcium carbide slag and alkali activator,the pozzolanic reaction of fly ash occurs;the main products of pozzolanic reaction are hydrated calcium silicate gel,ettringite and dihydrate gypsum.When the curing age was 360 d,Ca(OH)2 was not found obviously in the specimen,it indicated that the pozzolanic reaction was basically completed when cured soil specimen was cured for 360 d.