A Study on Granite Saw Dust & Fly Ash Blended Geopolymer Concrete Behavior with Various NaOH Molarities

This paper describes the experimental investigation carried out to develop geopolymer concrete based on alkali activated fly ash by Sodium Hydroxide with Sodium Silicate. The granite waste because of its fineness and size it can be effectively used as a replacement of sand. The strength of geopolymer concrete increases with the increase in the alkalinity of NaOH. Previous investigations on introduction of granite fines into ordinary concrete showed positive results at an optimum replacement of sand at 15 %. An attempt was made to introduce granite aggregate into geopolymer concrete as it increases the alkalinity of geopolymer concrete as well as it`s grading of sand. Effects of the factors such as method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer concrete were investigated. It was possible to achieve compressive strength 38 N/mm2for the geopolymer concrete after 8 days of casting when cured for 48 hours at 950 C. Results indicated that the increase of water content of all three forms of geopolymer resulted in decrease of the compressive strength. Strength development of geopolymer at room temperature was also studied and found that only half of the compressive strength of the heat cured sample was achievable even after 28 days. Most of the results were very promising and showed a great potential for this material as a substitute for Ordinary Portland Cement concrete. The granite aggregate was replaced in percentages various tests such as split tensile strength, compressive strength and flexural strengths were tested and compared with basic mix.