Statistical Modelling of Ultrasonic Pulse Velocity of Fly Ash Based Geopolymer mortar using response surface methodology

Abstract

The fly ash based geopolymer has emerged as a capable and sustainable binder material in construction industry. Ultrasonic pulse velocity (UPV) method is a non-destructive technique for investigating the mechanical performance of concrete. Experimental investigation was performed for studying the effect of NaOH Molarity, Na2SiO3/NaOH and curing temperature on the ultrasonic pulse velocity of geopolymer mortar. Experiments were designed based on central composite design (CCD) technique of response surface methodology (RSM). Statistical model was developed and statistically validated and found significant as the difference between adjustable R-squared and predicted R-squared less than 0.2. Finally, the optimized mix proportion was assessed for maximized value of UPV. Experimental validation on the optimized mix reveals the close agreement between experimental and predicted values of UPV with significance level of more than 95%. The proposed technique improves the yield, the reliability of the product and the processes.