Experimental Investigation on Molar Concentration of Sodium Hydroxide Solutions on Silica and Geopolymer Concrete

Generally Portland cement is used as a binding material in concrete which liberates large amount of CO2 while manufacturing. Hence there is an urgent need for proper attention and to minimize their impact on the sustainability of our living environment. In this study fly ash is fully replaced for cement and it is chemically activated by a high-alkaline solution. Another Artificial material called as Silica sand is used as the fine aggregate instead of river sand. Alkaline solution is the mixture of sodium hydroxide (NaOH) and sodium silicate ( Na2Sio3 ), which is used increase the binding property in concrete between the coarse aggregates and fine aggregates and other unreacted materials in mixture. The strength of the geopolymer concrete depends upon the molar raio of the alkaline solution. In this study concrete grade of M30 and Alkaline solution of sodium hydroxide (NaOH) and sodium silicate (Na2Sio3) of molarity 8M and 12M are used. The silica sand is replaced as fine aggregate ratios of 25%, 50% and 100%. The mechanical properties, Non destructive test (NDT) and durability tests are compared between the 8M and 12M molarity concentrations on 7, 14 and 28days results. The specimens are cured for 28 days at ambient room temperature.