差异含水率条件下飞灰及其螯合物的应力-应变及环境特性

摘要

垃圾焚烧飞灰因极高的重金属含量而被认为是一种危险废弃物,但与火山灰成分的相似使该材料有着资源化利用的潜在价值.以飞灰及其螯合物为研究对象,探讨了含水率、养护条件等因素对材料应力-应变及环境特性的影响.研究结果表明:飞灰螯合物重金属浸出浓度较低,并有着较强的吸水特性;飞灰及其螯合物强度早期随着养护时间的增长呈上升趋势,破坏应变随之减小,脆性不断增大;材料强度在中后期出现明显分化,飞灰(90％湿度养护)强度约为螯合飞灰的23.11倍.飞灰强度随含水率的增大而减小,可归结于孔隙水对压实能量的吸收和结构的影响;螯合飞灰强度均随养护时间和含水率增加而显著增大.%Fly ash,as a kind of solid waste,attracts increasing attention in the recent years.In this paper,the stress-strain and leaching behavior of fly ash and chelating fly ash under various moisture contents were studied.According to the test results,moisture content,curing conditions have significant effects on the compressive strength,failure strain.The heavy metals leaching from fly ash can almost meet the requirement of environment.The strength of fly ash and chelating fly ash rise with the increase of curing time,while the failure strain decreases at earlier period.In the later period of curing time,the compressive strength exhibits different trend,by which the strength of fly ash in curing boxes is about 23.11 times of the chelating fly ash.Among them,the strength of fly ash increases with the decrease of water content under different curing conditions,due to the influence of pore water on the absorption and structure of compaction energy;in addition,the strength of chelating fly ash in curing boxes increases with the increase of the curing time and water content.