Experimental study on municipal solid waste incineration ash micro-powder as concrete admixture

Abstract To improve the utilization rate of municipal solid waste incineration (MSWI) ash and achieve resource recycling, this article conducted research on grinding MSWI ash into fine powder for use as a concrete admixture. Initially, the physical and chemical properties of the MSWI ash micro-powder were tested. Subsequently, different amounts of MSWI ash powder concrete were prepared. The macro and micro properties of the concrete were then tested. Finally, a life cycle assessment was utilized to evaluate and compare ordinary concrete with MSWI ash micro-powder concrete. The results indicate that the chemical composition of the MSWI ash micro-powder is similar to that of cement clinker. It exhibits potential hydraulicity and a slow hydration reaction, making it an active admixture suitable for concrete raw materials. With the increasing proportion of MSWI ash micro-powder, the rate of hydration reaction in concrete slows down, resulting in decreased mechanical properties. The microhardness value of the hardened cement paste in MSWI ash micro-powder concrete is lower than that of ordinary concrete. Moreover, the addition of MSWI ash micro-powder helps mitigate the environmental impact of concrete in terms of non-biological energy loss and CO2 emissions.