The Effects of Some Agricultural Wastes Ash on the Compressive Strength of Concrete

Abstract

This research work examined the optimum compressive strength and density in sawdust ash and rice husk ash blended concrete. The reason for the research was due to the increase in green houses gas emission associated clinkers production for cement and also the ever-increasing cost of housing. The sawdust ash and rice husk ash concrete were prepared and replaced with cement at weighted percentages of 2 %, 4 %, 6 %, 8 %, 10 %, 12 %, 14 %, 16 %, 18 %, 20 % at 0.6 water/cement ratio. A total of one hundred and sixty-eight (168) concrete samples of 100 mm x 100 mm x 100 mm were produced and cured by immersion for 7 days, 14 days, 28 days, and 120 days respectively. The results show that at 120 days curing duration, the optimum density of the control concrete was reported as 2740Kg/m³ which was less than that of the sawdust ash and rice husk ash blended concrete density recorded as 2852 kg/m³ and 2919 Kg/m³ and obtained at 2 % replacement of SDA and RHA respectively. Also, the optimum compressive strength for the control concrete of 35.5 N/mm² was similarly obtained for saw dust ash and rice husk ash concrete but at 2 % and 12 % replacements cured at 120 days. Regression coefficient of linear multiple regression model was determined. The R² was recorded as 0.985964 and 0.906269 for SDA and RHA respectively which shows the adequacy of the linear model.