Influence of various design parameters on compressive strength of geopolymer concrete: A parametric study by taguchi method

Abstract

Global warming is one of the severe environmental effects, which are faced by the current generation. Studies show that Carbon dioxide (CO2) is the major cause of global warming and is mainly due to the huge production of Ordinary Portland Cement (OPC). Supplementary cementitious materials can reduce this effect by reducing the required materials instead of OPC for construction purposes. Geopolymer Concrete (GPC) is a new generation concrete, which does not require OPC. In this study, Fly Ash (FA) was used to produce GPC. Various parameters were considered and the design of the experiment was made using Taguchi's method and developed an empirical relation to predicting the compressive strength of GPC based on the different parameters. Thirty-six mixes were cast to determine the effect of curing temperature, curing time, rest period, the ratio of Alkaline Activator solutions (AAs), ratio of activators to FA, the molarity of NaOH and replacement level of FA with OPC on the compressive strength. The contribution of each parameter was estimated by ANOVA. Results show that the addition of OPC had a significant effect on the compressive strength of GPC. The mix with 20% OPC, 14M NaOH, curing temperature of 60oC, curing time of 36h, a rest period of 48h, AAs to FA ratio 0.3 and ratio of alkaline solutions 2.5 was found to have the maximum compressive strength. A regression equation is developed to determine the compressive strength of GPC concerning the parameters considered.