Sustainability Analysis of Hollow Concrete Blocks Manufactured Using Recycled Concrete Aggregate and Fly Ash as an Eco-Friendly Construction Component

Abstract

The present study focuses on the innovative technique for making rectangular and circular hollow concrete blocks using fly ash (FA) and recycled concrete aggregates (RCA). The feasibility of employing RCA in conjunction with fly ash as a substitute for natural aggregates and cement in a proportion ranging from 30%–90% and 15%–45%, respectively, is tested in the laboratory. According to current standards, the tests comprise the slump test, compressive strength test, water absorption test, and structural efficiency evaluation. An empirical quantitative technique is used for the cost–benefit analysis of a 100-square-foot model built with recycled concrete hollow blocks. The study suggests that employing recycled concrete aggregate and fly ash as replacements for conventional materials would result in a minimum cost savings of 17%. The quantity of greenhouse gases produced in CO2 equivalents during concrete production is calculated using the Inventory of Carbon and Energy database. According to research findings, the utilization of recycled concrete aggregates and fly ash reduced carbon dioxide equivalent emissions by 30%–40%. It was also confirmed that cement has a major effect on greenhouse gas emission generation throughout the concrete manufacturing phase, regardless of the use of RCA over virgin aggregates. This study intends providing a significant understanding of how RCA and FA can not only contribute to environmental conservation but also offer economic benefits. Finally, the research intends to encourage the adoption of ecologically responsible and economically viable sustainable practices in the construction industry.