Physiochemical and Mechanical Performance of Portland Cement Grades Marketed in Nigeria

This study presents a comparative assessment and analysis of the hydration properties of Portland cement grades 32.5 and 42.5 marketed in Calabar, Cross River State, Nigeria. The research was motivated by concerns over inconsistent cement quality and its impact on structural performance. Five (5) cement samples (A, B, C, D and E) were analyzed for chemical composition (XRF), physical properties (Blaine fineness, residue, consistency, expansion, and setting times), and mechanical properties (compressive and flexural strength at 2, 7, and 28 days). Results from Blaine values ranged from 3940 to 4480 cm²/g, showed sample D (32.5R) exhibiting the highest fineness. Setting times (initial: 133 to 155 min; final: 205 to 216 min) and expansion values (0.5 to 1.0 mm) were within permissible limits. Strength development increased with curing age, with 42.5R achieving the highest 28-day flexural strength (5.8 MPa), outperforming 32.5R (4.7 to 5.0 MPa).The findings confirm that while both cement grades meet national and international standards, 42.5 grade cements offer superior hydration performance and strength, making them more suitable for high-strength structural applications, whereas 32.5grade cements are better suited for light construction and finishing works. The research result showed analyses that falls within the acceptable range of the National and International Standards, and the coefficient of variation indicate the robustness and reliability of the result. And objectives of the assessment were fully achieved, with empirical data guide in cement selection, improving production quality, and support regulatory enforcement in Nigeria’s construction industry.