Experimental Investigation of Opuntia ficus-indica Mucilage as a Concrete Admixture for Sustainable Construction

Abstract

The key properties of concrete are often controlled using synthetic admixtures, despite their possible adverse environmental effects. This study tested the potential of Opuntia ficus-indica (OFI) liquid mucilage as a natural and sustainable concrete admixture, assessing its effects on setting time, workability, consistency, and compressive strength of conventional concrete. The research applied an experimental approach, incorporating both direct addition (0.5-5%) and partial replacement of mixing water (0.5-30%), with performance comparisons against the commercial admixtures Sika and Darma. The results indicated that adding OFI mucilage significantly improves workability, enhances moisture retention, and extends setting time, making it a viable alternative for hot-climate construction. Optimal dosages of 1 - 1.5 % increased the 28-day compressive strength by up to 9%, outperforming the conventional admixtures. However, excessive dosages (>2%) negatively affect the strength. Partial cement replacement with mucilage also improved early and long-term strength while reducing permeability. As a natural and locally available admixture, the findings highlight the potential of OFI to reduce reliance on imported chemicals and to lower carbon dioxide emissions. In conclusion, OFI mucilage is a multifunctional concrete admixture, excelling in setting time modification, workability enhancement, and strength optimization, while offering economic and environmental advantages for sustainable construction practices, making it cost-efficient and resource-conscious infrastructure development.