Corn Cob Ash as a Partial Cement Replacement in Concrete: A Critical Review of Processing, Fresh Properties, Strength, Durability and Research Needs

Corn cob ash has credible potential as a supplementary cementitious material, but its usefulness is conditional rather than automatic. The literature shows that CCA can contribute to sustainable concrete by reducing cement demand and valorizing agricultural residue, while properly processed ash can contribute to pozzolanic reaction and matrix refinement. At the same time, untreated or poorly controlled ash can have high alkali, chloride or unburnt-carbon contents and may reduce workability or compressive strength. Across the literature, low replacement levels around 5–10% are repeatedly identified as a practical range for further investigation, although the optimum cannot be fixed independently of ash source, processing, cement type and mixture design. The author's M.Tech work, which uses PPC-based M20 concrete and investigates CCA replacement up to 15%, fits within this research direction. Its reported observation that a low replacement level performs favorably is consistent with the broader literature, but it should remain a system-specific conclusion. The most important requirement for future publication-quality work is therefore reproducibility. A paper should allow another researcher to reproduce the ash, understand its chemistry and fineness, reproduce the concrete mixture, and evaluate both strength and durability. If these details are controlled, CCA can move from a general waste-utilization concept toward a technically defensible supplementary cementitious material for selected concrete applications.

1.      Neville, A. M. (2012). Properties of Concrete. 5th ed. Pearson/Trans-Atlantic Publications. 2.      Mehta, P. K., & Monteiro, P. J. M. (2014). Concrete: Microstructure, Properties, and Materials. 4th ed. McGraw-Hill Education. 3.      Scrivener, K. L., John, V. M., & Gartner, E. M. (2018). Eco-efficient cements: Potential economically viable solutions for a low-CO₂ cement-based materials industry. Cement and Concrete Research, 114, 2–26. https://doi.org/10.1016/j.cemconres.2018.03.015 4.      Ahmad, J., Arbili, M. M., Alabduljabbar, H., & Deifalla, A. F. (2023). Concrete made with partially substitution corn cob ash: A review. Case Studies in Construction Materials, 18, e02100. https://doi.org/10.1016/j.cscm.2023.e02100 5.      Adesanya, D. A., & Raheem, A. A. (2009). Development of corn cob ash blended cement. Construction and Building Materials, 23(1), 347–352. https://doi.org/10.1016/j.conbuildmat.2007.11.013 6.      Adesanya, D. A., & Raheem, A. A. (2009). A study of the workability and compressive strength characteristics of corn cob ash blended cement concrete. Construction and Building Materials, 23(1), 311–317. https://doi.org/10.1016/j.conbuildmat.2007.12.004 7.      Adesanya, D. A., & Raheem, A. A. (2010). A study of the permeability and acid attack of corn cob ash blended cements. Construction and Building Materials, 24(3), 403–409. https://doi.org/10.1016/j.conbuildmat.2009.02.001 8.      Adesanya, D. A. (1996). Evaluation of blended cement mortar, concrete and stabilized earth made from ordinary Portland cement and corn cob ash. Construction and Building Materials, 10(6), 451–456. https://doi.org/10.1016/0950-0618(96)00001-3 9.      Olafusi, O. S., & Olutoge, F. A. (2012). Strength properties of corn cob ash concrete. Journal of Emerging Trends in Engineering and Applied Sciences, 3(2), 297–301. 10.      Mujedu, K. A., Adebara, S. A., & Lamidi, I. O. (2014). The use of corn cob ash and saw dust ash as cement replacement in concrete works. International Journal of Engineering and Science, 3(4), 22–28.