Development of metakaolin based high strength recycled aggregate geopolymer concrete

Abstract

In order to address the environmental impact of the construction industry, it is necessary to adopt sustainable and eco-friendly practices. One such solution is the development of geopolymer binder with recycled aggregate concrete, which can reduce the consumption of ordinary Portland cement and natural aggregates. This study aimed to improve the quality of high-strength recycled aggregates geopolymer concretes by incorporating metakaolin in varying percentages and adhering to DIN specifications for maximum particle packing. Six different mixes were developed, including three separate alkaline activate content/binder's ratio and metakaolin at 10% and 15% replacement levels. The study investigated the impact of these green mixtures on fresh and hardened properties such as compressive strength, split tensile and elastic modulus, as well as durability factors such as sorptivity and water permeability, which were supported by microstructural study (SEM and XRD). The results showed that these green mixtures exhibited excellent mechanical and durability performance, making them suitable for various construction projects. � 2023 Elsevier Ltd