Compressive Strength of Ternary Blended Geopolymer Concrete Composites

Use of industrial wastes as supplementary concreting materials in the manufacturing of concrete is very vital at present to obtain a sustainable environmental solution. Some of the commonly used pozzolanic materials are Fly ash, Ground Granulated Blast Furnace Slag (GGBS), Silica Fume and Rice Husk Ash (RHA) etc. In the present experimental investigation, the compressive strength property of ternary blended geopolymer concrete has been studied by considering Fly ash, Ground Granulated blast furnace slag (GGBS) and Rice Hush Ash (RHA) in various percentages as source materials for geopolymerisation. The source materials were activated with alkaline activators consisting of a combination of Sodium Hydroxide (NaOH) & Sodium Silicate (Na2SiO3) solutions with the concentration of NaOH being 10 molarity (10M). For various combinations of Fly ash, Rice Husk ash and GGBS the compressive strength for 7 days and 28 days were determined experimentally. From the test results, it has been found that as the GGBS content increases, the compressive strength of the concrete also increases whereas, as the content of RHA increases, the density and compressive strength of the concrete decreases. The optimum combination was found to be F60 G30 R10 and F70 G20 R10 for which the compressive strength of the concrete is 34.67 MPa and 24.87 MPa which can be used in applications where M30 and M20 grades of concrete are required. The density of F60 G30 R10 GPC is 2320 kg/m3 which is lesser than conventional concrete. It is also found that usage of 90% of rice husk ash in geopolymer concrete is not at all effective. The obtained compressive strengths are in the range of 10 MPa to 34.0 MPa which depends on the ratio of GGBS to RHA. Proper consumption of the RHA contributes in solving the environmental pollution and also to improve the environmental friendliness of concrete to make it suitable as a green building material.