Incineration has been widely adopted as a solution to the increasing volume of municipal solid waste(MSW).However,this process generates substantial amounts of incineration bottom ash(IBA),which poses environmental ri...Incineration has been widely adopted as a solution to the increasing volume of municipal solid waste(MSW).However,this process generates substantial amounts of incineration bottom ash(IBA),which poses environmental risks due to heavy metal content,especially in the fine fraction(FIBA).In this context,this study proposes producing liquefied stabilized soil(LSS)from FIBA,marine clay(MC),and ground granulated blast furnace slag(GGBS)for backfilling applications.FIBA serves as an alkaline activator for GGBS hydration,while MC functions as the primary soil matrix.GGBS acts as the primary binder.Carbide sludge(CS),another industrial byproduct,was used as a comparison to FIBA.The performance of the fresh and solidified LSS,including flow value,unconfined compressive strength(UCS),and leaching of heavy metals was investigated.The results showed that with proper contents of FIBA,water,and binder,the flow value of FIBA-GGBS-clay and CS-GGBS-clay satisfied the workability requirements.With increasing CS content,the UCS of CS-GGBS-clay initially increased sharply,then gradually reached an optimal value,and slightly decreased in some cases.Nevertheless,as FIBA content increased,the UCS of FIBA-GGBS-clay generally increased linearly.With similar Ca(OH)2 contents,FIBA-GGBS-clay had a higher strength than CS-GGBS-clay due to the soil skeleton effect of sand-sized particles in FIBA.The synergy of CS and FIBA enabled CS-FIBA-GGBS-clay to achieve high early strength while addressing the high heavy metal content issue of FIBA.Overall,this approach can be adapted to meet the varying strength and heavy metal requirements of LSS in different applications.展开更多
The hydration properties of cement-GGBS-fly ash blended binder and cement-GGBS-steel slag blended binder were compared. The experimental results show that the hydration rate of cement-GGBS- steel slag blended binder i...The hydration properties of cement-GGBS-fly ash blended binder and cement-GGBS-steel slag blended binder were compared. The experimental results show that the hydration rate of cement-GGBS- steel slag blended binder is higher than that of cement-GGBS-fly ash blended binder within 28 days, but lower than the latter after 28 days. The hydration of cement-GGBS-steel slag blended binder tends to produce more Ca（OH）2 than the hydration of cement-GGBS-fly ash blended binder, especially at late ages. Cement-GGBS- steel slag mortar exhibits higher strength than cement-GGBS-fly ash mortar within 28 days, but at late ages, it exhibits similar compressive strength with eement-GGBS-fly ash mortar and even slightly lower bending strength than cement-GGBS-fly ash mortar. Cement-GGBS-steel slag paste has finer early pore structure but coarser late pore structure than cement-GGBS-fly ash paste. Cement-GGBS-steel slag paste can get satisfied late pore structure and cement-GGBS-steel slag mortar can get satisfied late strength as compared with pure cement paste and pure cement mortar, respectively.展开更多
基金supported by BETA Catalyst Funding Grant(Grant No.BETA-20240222005)from Building and Construction Authority(BCA),Singapore.
文摘Incineration has been widely adopted as a solution to the increasing volume of municipal solid waste(MSW).However,this process generates substantial amounts of incineration bottom ash(IBA),which poses environmental risks due to heavy metal content,especially in the fine fraction(FIBA).In this context,this study proposes producing liquefied stabilized soil(LSS)from FIBA,marine clay(MC),and ground granulated blast furnace slag(GGBS)for backfilling applications.FIBA serves as an alkaline activator for GGBS hydration,while MC functions as the primary soil matrix.GGBS acts as the primary binder.Carbide sludge(CS),another industrial byproduct,was used as a comparison to FIBA.The performance of the fresh and solidified LSS,including flow value,unconfined compressive strength(UCS),and leaching of heavy metals was investigated.The results showed that with proper contents of FIBA,water,and binder,the flow value of FIBA-GGBS-clay and CS-GGBS-clay satisfied the workability requirements.With increasing CS content,the UCS of CS-GGBS-clay initially increased sharply,then gradually reached an optimal value,and slightly decreased in some cases.Nevertheless,as FIBA content increased,the UCS of FIBA-GGBS-clay generally increased linearly.With similar Ca(OH)2 contents,FIBA-GGBS-clay had a higher strength than CS-GGBS-clay due to the soil skeleton effect of sand-sized particles in FIBA.The synergy of CS and FIBA enabled CS-FIBA-GGBS-clay to achieve high early strength while addressing the high heavy metal content issue of FIBA.Overall,this approach can be adapted to meet the varying strength and heavy metal requirements of LSS in different applications.
基金Funded by the National Natural Science Foundation of China(No.51108245)the China Postdoctoral Science Special Foundation(No.201104119)
文摘The hydration properties of cement-GGBS-fly ash blended binder and cement-GGBS-steel slag blended binder were compared. The experimental results show that the hydration rate of cement-GGBS- steel slag blended binder is higher than that of cement-GGBS-fly ash blended binder within 28 days, but lower than the latter after 28 days. The hydration of cement-GGBS-steel slag blended binder tends to produce more Ca（OH）2 than the hydration of cement-GGBS-fly ash blended binder, especially at late ages. Cement-GGBS- steel slag mortar exhibits higher strength than cement-GGBS-fly ash mortar within 28 days, but at late ages, it exhibits similar compressive strength with eement-GGBS-fly ash mortar and even slightly lower bending strength than cement-GGBS-fly ash mortar. Cement-GGBS-steel slag paste has finer early pore structure but coarser late pore structure than cement-GGBS-fly ash paste. Cement-GGBS-steel slag paste can get satisfied late pore structure and cement-GGBS-steel slag mortar can get satisfied late strength as compared with pure cement paste and pure cement mortar, respectively.
