Influence of activator solution on microstructural and mechanical properties of geopolymer concrete

Abstract

Geopolymer Concrete (GC) is an innovative and Eco-friendly construction material and an alternative to Portland cement concrete. The binders such as fly ash, Ground Granulated Blast Furnace Slag (GGBS), and cement used to produce GC in this research work. These binders activated through two types of solutions (an alkaline solution which prepared in the laboratory and activator solution purchased commercially). An attempt has made to observe the advantages of commercially available activator solutions on properties of GC. The test results of laboratory prepared alkaline solution based GC specimens compared with commercially available activator solution based GC. The mechanical properties were investigated with 20% and 30% addition of GGBS and cement to fly ash based GC samples. Besides, the analysis of the specimen through SEM and EDS indicated that the components having a considerable influence on the structure of the GC were the Al and Si components. The XRD results revealed that there were no practical differences in the intensity according to the differences in the chemical elements of the alkaline/activator solutions. However, the TG/DT analysis made it possible to identify changes in mass loss of different proportions based GC. The alkaline solution based mixes attained enhanced mechanical properties compared to activator solution based GC samples. The microstructural studies revealed the reasons behind the strength improvement of fly ash-GGBS based GC.