Decarbonizing Cement with Optimized Sugarcane Bagasse Ash: A Path to Greener Infrastructure

The growing demand for sustainable infrastructure has accelerated the search for low-carbon alternatives to ordinary Portland cement (OPC). This study explores the potential of sugarcane bagasse ash (SBA), an abundant agro-industrial residue, as a supplementary cementitious material (SCM). SBA was subjected to controlled calcination at temperatures of 600–1000°C and durations of 1–5 hr, followed by mechanical grinding to achieve uniform fineness. The processed SBA was incorporated into cement at substitution rates of 5–30% and its effects on physical, mechanical and microstructural performance were systematically evaluated. Results show that calcination at 700°C for 3 hr produced ash with enhanced pozzolanic activity due to the preservation of amorphous silica. At replacement levels of 15–20%, the mix exhibited balanced workability, reduced hydration heat and progressive strength gain, surpassing 55 MPa by 180 days and reaching 57.4 MPa at 270 days, comparable to or exceeding OPC benchmarks. The present work demonstrates that optimally processed SBA can effectively replace a substantial fraction of cement while maintaining structural performance. Beyond technical feasibility, the approach significantly reduces carbon emissions and supports circular economy practices by valourizing agricultural waste, offering a practical, eco-efficient pathway for decarbonizing OPC and advancing greener construction materials.