Synthesis and Characterization of Fly Ash and GBFS Based Geopolymer Material

Abstract

This study investigates the synthesis and characterization of fly ash and GBFS based material using geopolymer technology. Geopolymer is a class of inorganic polymer that can be formed by the reaction between an aluminosilicate source material and an alkaline solution. The geopolymer materials are synthesized, where the GBFS are added with fly ash in some specific ratios such as 100:0, 30:70, 50:50, 70:30, and 0:100, respectively. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solutions are used as alkaline solutions. NaOH concentration was kept at 14 molars, and the ratio of liquid to solid is kept at 0.3. The specimens are cured at 60 oC for 24 hours. The hardened geopolymer specimens were tested by a digital compression testing machine and characterized by the FESEM technique. The hybrid C-N-A-S-H gel is the main reaction product for the fly ash and GBFS based geopolymer specimen, which plays an important role in compressive strength development.