Title:
Characterization of Fly Ashes for Sulfate Resistance
Author(s):
Rajaram Dhole, Michael D. A. Thomas, Kevin J. Folliard, and Thano Drimalas
Publication:
Materials Journal
Volume:
110
Issue:
2
Appears on pages(s):
159-168
Keywords:
characterization; chemistry; fly ash; mineralogy; sulfate resistance.
DOI:
10.14359/51685530
Date:
3/1/2013
Abstract:
The sulfate resistance of mixtures containing six fly ashes was studied with reference to their chemical and mineralogical compositions. Quantitative analysis of the mineralogical composition of fly ashes was carried out through X-ray diffraction (XRD) using the Rietveld method of analysis. Bulk and glass composition of the fly ash particles was also determined by using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA). The sulfate resistance of fly ash mortars was evaluated using the ASTM C1012/C1012M test. The performance of each fly ash in the sulfate resistance test was related to the chemical and mineralogical composition of the fly ash and its position on the ternary (CaO-SiO2-Al2O3) diagram. The study showed that the nature of glass is an important factor in determining the sulfate resistance of fly ash mixtures in a sulfate environment.