A Review of the Use of Corncob Ash as a Supplementary Cementitious Material

It has been argued that cement is the most energy intensive and expensive material in concrete. It has also been suggested that energy efficiency could be achieved by using Supplementary Cementitious Materials (SCMs), which require less process heating and emit fewer levels of CO2. This paper reviewed studies from different authors on the possibility of using Corn Cob Ash (CCA) as a SCM. The review targeted studies that had applied the quantitative method, with validity and reliability based on empirical data from laboratory experiments. The review covered workability, density, compressive and tensile strengths, gain in strength over time, water absorption and chemical resistance of CCA-replaced concrete. From the findings, it can be concluded that CCA could be used as an effective SCM to replace cement in concrete, with the benefit of a reduction in CO2 emissions that are associated with the production of cement and a mitigation on environmental nuisance that is attributed to the throwing away of corncobs and CCA in landfill, while at the same time improving the properties of wet and hardened concrete.