Towards closed-loop concrete recycling: Life cycle assessment and multi-criteria analysis

Abstract

In this study, a wide-ranging life cycle assessment and multi-criteria analysis for close-loop cycling of concrete are conducted. Considering six performance keys in the technical (compressive strength at short and long ages), environmental (human health, ecosystem quality, climate change, resources), and economic (costs), a solid framework is created and analyzed by three multi-criteria decision-making techniques, namely, TOPSIS, VIKOR, and EDAS. The weight that must be taken into account for each of the applied criteria depends on the specific application and the demands of the user. Nevertheless, two different weighted methods, namely, the equal performance method and the entropy method, have been employed in this work to optimize for various construction-related applications, specifically sustainable residential buildings and residential housing. The findings demonstrate that the concrete mixtures produced with 20% FA+12% SF and MRCA incorporation are the best in terms of the criteria used for all applied techniques and the two weighted methods. This study demonstrates that multi-criteria decision-making techniques are simple to apply, requiring minimal time and effort and focusing on the finished result, allowing users to choose the best concrete mixtures. The proposed framework recommends the closed-loop recycling of concrete by introducing supplementary cementitious materials for sustainable, economical, and performance-based design applications.