Effects of Cement Additives on Alinite Cement-Based Materials from Municipal Solid Waste Incineration (MSWI) Fly Ash

Abstract

Municipal solid waste incineration (MSWI) fly ash was successfully used as a main raw material in sintering and preparing alinite cement clinker in laboratory. Based on this, this work focused on the effects of cement admixtures on the compressive strength and durability of the alinite cement-based materials. The optimum mix mass ratio was confirmed, i.e. the mass ratio of alinite cement clinker / gypsum / cement additives (MSWI fly ash, fly ash, or slag) was 80 % / 5 % / 15 %. The experimental results showed that addition of cement additives could improve resistance to sulfate attack of the prepared alinite cement-based materials. The resistance to carbonation and water permeability could be improved by adding different cement additives. The effectiveness is specimen AD3 (with 15 wt. % slag) > AB3 (with 15 wt. % MSWI fly ash) > AC3 (with 15 wt. % fly ash). However, addition of cement additives had negative effects on the dry shrinkage. Finally, with the hydration ages increasing, the content of soluble chloride ion from alinite cement specimen AB3 was decreased. It would be stable in long term. This work improves utilization of industrial solid wastes as cement additives in the prepared alinite cement from MSWI fly ash. It is beneficial for our understanding and application of alinite composite cement as construction and building materials.