Evaluation of Anogeissus leiocarpus ash as a pozzolanic material for concrete in chemical environments

Addressing the pressing need for sustainable construction materials amidst rising cement costs, environmental degradation, and global warming, this study investigates the potential of Anogeissus leiocarpus ash as a partial cement replacement in concrete exposed to chemical environments. Unlike conventional focus on compressive strength alone, this research holistically evaluates mechanical and durability properties. Preliminary material characterization was conducted, followed by casting 252 concrete samples (100 mm cubes) with 0%, 5%, 10%, 15%, 20%, and 25% Anogeissus leiocarpus ash substitutions using a 1:2:4 mix proportion (cement: fine aggregate: coarse aggregate) and 0.63 water-cement ratio. Assessments at 28 and 56 days encompassed compressive strength, abrasion resistance, and water absorption (sorptivity) in normal and magnesium sulphate (MgSO4) environments. Compressive strength at 28 days showed a marginal decrease of 0.84% for 20% ash replacement concrete versus control samples in normal curing. Concrete with Anogeissus leiocarpus ash exhibited superior abrasion resistance and lower sorptivity compared to Ordinary Portland Cement (OPC) counterparts in both normal and chemical environments at 56 days. The ash demonstrated pozzolanic properties, satisfying ASTM C618-22 criteria. The distinctiveness of Anogeissus leiocarpus ash lies in its local availability and underutilized potential as a sustainable pozzolan, offering dual benefits of reduced clinker dependency and enhanced concrete durability in aggressive environments, positioning it as a viable candidate for eco-friendly construction material balancing performance and environmental stewardship.