Characteristics of municipal solid wastes incineration (MSWI) fly ash–cement matrices and effect of mineral admixtures on composite system

An experimental work was carried out to investigate the feasibility of application of MSWI fly ash as an auxiliary cementitious material. The water demand for normal consistency, setting time, volume stability, flexural and compressive strength of MSWI fly ash–cement compound matrices were tested. And, the composite effect and the influence of mechanical properties and heavy metals solidification are studied by mixing MSWI fly ash–cement matrices with common mineral admixtures. The results show that the MSWI fly ash has some cementitious activity, but the reactivity is relatively lower and its addition to cement may lead to retardation of cement hydration. After incorporation of common mineral admixtures, the strength of solidified body was enhanced, and the effect of the heavy metals-immobilizing may be reinforced.