Utilization of municipal solid waste incineration bottom ash in blended cement

The objective of this study was to assess the feasibility of application of municipal solid waste incineration (MSWI) bottom ash as a supplementary cementitious material for the preparation of blended cement. The water demand for normal consistency, setting time, strength and hydration characteristics of MSWI bottom ash-cement compound matrices were investigated. The results show that the MSWI bottom ash has some cementitious activity, but the reactivity is relatively lower than Portland cement and its addition to cement may lead to retardation of cement hydration. The incorporation content of MSWI bottom ash in blended cements was controlled below 30%, which resulted in blended cement of strength class 32.5 according to GB 175-2007 (Chinese National Standard). It is also evident that heavy metal concentrations in leachates of the blended cements with MSWI bottom ash are far lower than recommended in the GB5085.3-2007.