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

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.