Environmental and mechanical analysis of low-carbon concrete with vitrified MSW incineration bottom ash as cement replacement

Abstract

The building sector is responsible for about 37% of the global carbon dioxide emissions, 6% of which result from concrete (and particularly cement) production. Using recycled and supplementary cementitious materials and adopting a whole building life cycle approach can be seen as multi-beneficial strategies for materials' design. In this framework, this study aims to formulate a green concrete, by replacing 10, 15 and 20% of cement with a secondary raw material constituted of vitrified bottom ash derived from municipal solid waste incineration. The basic physical and mechanical properties were measured up to 365 days, so to evaluate the effects of the cement replacement both on short and long-term behavior. Life Cycle Assessment was used as a tool to evaluate the environmental performance of the developed green concrete. An Eco-Mechanical Analysis was also performed to match the environmental impacts with the mechanical behavior, allowing to assess that the concrete produced by replacing 20% of cement with vitrified municipal solid waste incineration bottom ash (if classified as hazardous waste) is the one that leads to optimize the overall sustainability. The approach proposed in this work, which can be easily generalized, contributes to the definition of a route for the implementation of innovative green construction building materials by using waste.