Strength and Acid Resistance Evaluation of Geopolymer Concrete with Partial Replacement of Fly Ash by GGBS and Phosphogypsum

Abstract

Geopolymers are a new promising binder manufactured by activation of a solid alumino silicate source material with a highly alkaline activating solution and aided by heat. Fly ash, considered to be a waste material is rich in silica and alumina and hence can be used as a source material for manufacture of Geopolymers. These binders have been reported to achieve high early strength and better durability as compared to Ordinary Portland cement based counterparts. This paper presents the progress of the research on making GeoPolymer Concrete with Flyash and mineral admixtures such as GGBS and Phosphogypsum. The paper reports results of experimental study on development of compressive strength and Acid resistance of Geopolymer concrete. In this study an attempt has been made to produce Flyash based GeoPolymer concrete with partial replacement of Flyash with GGBS and Phosphogypsum and study the strength and durability properties of produced Geopolymer concrete. An experimental study was conducted to assess the compressive strength and acid resistance of Flyash based Geopolymer concrete specimens of size 150 X 150 X 150 mm having GGBS and Phosphogypsum as replacement from 0, 2.5, 5, 7.5, 10 % of Flyash . Acid Resistance is assessed by immersion of the above specimens in the solution of 5 % concentrated Sulphuric acid for a period of 30,60 and 90 days and evaluated the changes in weight and compressive strength at these intervals. The visual appearance of specimens after exposure to Sulphuric acid solution showed that acid attack slightly damaged the surface of the specimen. The produced Geopolymer concrete sample showed less weight loss in Sulphuric acid and having more residual compressive strength at the end of test. Geopolymers blended with GGBS and Phosphogypsum are having higher compressive strength and resistance to Sulphuric acid.