Geopolymer with brick and concrete demolition constructions waste

Abstract

The production of building materials impacts non-renewable resources through excessive raw material extraction and fossil resource consumption. This study investigates alternatives to Portland cement concrete by valorizing construction and demolition waste (CDW), including brick and reinforced concrete. The objective is to replace or eliminate clinker using geopolymers while incorporating CDW as recycled aggregates. Sustainable concretes were developed, such as geoconcrete with 0% clinker and 50% recycled aggregate, along with blends containing varying CDW percentages for structural applications. Results indicate that geopolymers with 100% ground granulated blast furnace slag (GBFS) achieve properties comparable to reference concrete. However, mixtures with recycled brick and concrete show lower strength due to low molarity and recycled aggregate usage. Elastic modulus increases with 100% GBFS but decreases by less than 10% with CDW. In beams, breaking moments reduce by up to 30% with 25% CDW, while brick-based mixtures demonstrate higher energy absorption.