Evaluating Properties and Microstructures of Fly Ash Based Geopolymer Using Laboratory Grade and Industrial Grade Alkaline Activators

Abstract

The replacement of Portland cement consumption by using fly ash-based geopolymer can reduce a huge amount of carbon dioxide emission from Portland production. Geopolymer is synthesized by mixing alkaline solutions with pozzolanic materials which mainly contains silica and alumina. At the present, most of the research studies are focusing on the usage of laboratory grade of alkaline solutions, which is quite expensive and impractical in real use. Therefore, the industrial grade of alkaline solution is selected to be used. The results showed that the compressive and flexural strengths of that geopolymer from the industrial grade solution were higher than that of the laboratory grade solutions in some specific conditions. The maximum compressive strength of the geopolymer from industrial grade solution and laboratory solution were 373.1 ksc and 343.1 ksc, respectively. While the maximum flexural strengths were 195.0 ksc and 149.1 ksc, respectively. From the results, it can be said that geopolymer from industrial grade of alkaline solutions can be used as a substitution for geopolymers production.