Characterization of Local Metakaolin Powder for Application as Geopolymer Precursor for Concrete Binder

It is known that metakaolin powder has proved to be a promising alternative concrete binder to Ordinary Portland cement (OPC). Portland cement production contributes about 8% to the global CO2 emission, which is detrimental to the environment and a major contributor to global warming. It is therefore pertinent to develop alternative costeffective and environmentally friendly cement materials. This study examines the performance of a Nigerian metakaolin-based powder as a sustainable material alternative to Portland cement. The Gwaram-Alkaleri Kaolin clay from Bauchi State, Nigeria, was calcined at 800°C for 3 hours as step prior to metakaolin formation. The powder specimens were characterized using XRF, moisture content, specific gravity, density, particle size distribution analysis and specific surface area techniques. Parametric analyses of the values of the specific gravity, density, particle size distribution and specific surface area were undertaken and comparisons and deductions made. The results revealed that Gwaram-Alkaleri metakaolin-powder can serve as a potential sustainable construction material for the Nigerian construction industry because of its availability, affordability, physical and chemical properties values, and significant reduction in CO2 emission, taking cognizance that the results positively indicate that it can be used as an alternative binding powder to cement in concrete and mortar production.