Study on fly ash ggbs based ambient cured geopolymer concrete

Abstract

Concrete manufactured using eco-friendly materials is a welcoming trend in current global scenario. In parallel to the trend, Geopolymer concrete was noticed as the most prominent one since different industrial by-products were used as a base material. In addition, geopolymer concrete acted as suitable replacement for Ordinary Portland Cement (OPC) based concrete which in turn minimized the emission of carbon dioxide into atmosphere. This led to the reduction of global warming effect there by addressing environmental issues caused by the use of OPC. This study attempted to produce the geopolymer concrete at ambient curing conditions by using fly ash, Ground Granulated Blast furnace Slag (GGBS), lower concentration of alkaline activator and bio-additives (Terminalia chebula and natural sugars). Different properties such as mechanical properties, durability properties and microstructural properties were investigated on fly ash- GGBS based ambient cured geopolymer concrete. Mechanical tests namely slump test, workability test, compression test, splitting tensile test and flexural test were carried out. Durability properties were assessed by acid attack test, sulfate attack test and chloride attack test. Microstructural properties were found out by using Atomic Force Microscopy (AFM), Mercury Intrusion Porosimetry (MIP), X-Ray Diffraction (XRD), Fourier Transform Infra-Red spectral (FTIR), Thermal Gravimetric (TG/DTG) and Scanning Electron Microscopic (SEM) studies. Test results showed that there was increase in workability and prolonged setting time of bio-additives added geopolymer mixes. In general, geopolymer concrete specimens containing Terminalia chebula and natural sugars displayed better compressive strength, splitting tensile strength and flexural strength when compared to control geopolymer concrete specimens at ambient curing conditions. newline