Effects of temperature, time and alkaline solution content on the mechanical properties of Class C fly ash-based geopolymer using Taguchi method

Abstract

This research aims to investigate the effects of three factors on the compressive strength of fly ash-based geopolymers by using the Taguchi method. The three studied factors include curing time, curing temperature and the percentages of NaOH and KOH in the alkaline solution. X-ray fluorescence spectrometry (XRF), Fourier Transform Infrared spectroscopy (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM) and mechanical tests were applied for characterization of raw materials and geopolymers samples. The results of the analysis have shown that the highest compressive strength achieved was 13.58 MPa and the optimum curing temperature, curing time and alkaline solution content were determined as 70°C, 24h and a mix of 50% NaOH/ 50% KOH respectively.