Progress on the Use of Rice Husk Ash (RHA) as a Construction Material in Nigeria

Research on the use of Rice Husk Ash (RHA) in cement, concrete and mortar has been explored in different fronts in Nigeria with encouraging results. RHA is composed of silica, alumina, iron oxide, calcium oxide and some traces of other compounds. The combustion of RHA at optimum temperature established by researchers produces either amorphous or crystalline ash depending on the combustion temperature and type of burning. This paper tries to bring under one umbrella documented research reported in literature on the use of RHA in construction in Nigeria. Physical and chemical properties; consistency, setting time and flow of mixed paste are reported. Combustion process and optimum temperature has also been exclusively reported. Cement replacement with RHA, strength results on concrete, mortar, bricks and blocks; other properties reported are flexural and tensile strength, sorptivity and coefficient of water absorption