Influence of Alkali Solution Types on Compressive Strength and Microstructure of Geopolymer Manufactured From Low Calcium Fly Ash Containing Ground Blast Furnace Slag
Tanakorn Phoo-ngernkham ^1* Sakonwan Hanjitsuwan ² Jirayut Suebsuk ¹ and Jaksada Thumrongvut ^1
1 Department of Civil Engineering, Faculty of Engineering and Architecture, Rajamangala University of Technology Isan.
² Program in Civil Technology, Faculty of Industrial Technology, Lampang Rajabhat University.

Abstract

This article investigated the influences of alkali solution on compressive strength and microstructure of geopolymer manufactured from low fly ash (FA) containing ground blast furnace slag (GBFS). The FA was replaced with GBFS at the dosages of 0, 50 and 100 by weight of binder. The FA-GBFS blends were activated with 10 molar sodium hydroxide solutions directly (NH), sodium silicate and sodium hydroxide solutions together (NHNS), and sodium silicate directly (NS) for using as the liquid portion in the mixture. Alkaline liquid/binder ratio of 0.60 and curing at ambient temperature of 25 oC were selected for all mixtures. The results indicated that the increase in GBFS enhanced the compressive strength and microstructure of geopolymer pastes due to additional calcium silicate hydrate into the geopolymer matrix. While the alkali solutions had significance effects on the geopolymerization products.