Analysis of reaction degree and factors of alkali-activated fly ash/slag

Abstract

This paper investigates the dissolution rates of alkali-activated fly ash and alkali-activated slag in hydrochloric acid(HCl) with various pH values. XRF, XRD, and FTIR were used to analyze the HCl-insoluble matter of alkali-activated fly ash and alkali-activated slag. The geopolymerization reaction degree of alkali-activated fly ash/slag can be determined based on the content of HCl-insoluble matter. The acid dissolution tests of alkali-activated fly ash/slag show that adding slag increases the geopolymerization degree of fly ash in most cases. With a certain slag content, the reaction degree of fly ash decreases with the increase of activator modulus and increases with the liquid/solid ratio. The increase of the activator concentration has a more pronounced effect when the slag content is low. At low activator concentration, the reaction degree of fly ash increases with the increase of slag content. The slag content corresponding to the highest reaction degree of fly ash is gradually reduced with the increased activator concentration.