Chemical Attack on Alkali-Resistant Glass-Fibers in a Hydrating Cement Matrix - Characterization of Corrosion Products

Abstract

This paper reports the corrosion behaviour of zirconium-containing, alkali-resistant glass fibres in a Portland cement paste cured for one year. The alkali-resistant glass fibres are attacked by hydroxyl ions in the pore fluids of hydrated Portland cement matrices. The chemical attack leads to hydroxylation of the glass fibre surfaces. During the hydroxlation process, the glass fibres developed a shell-core morphology. The shell consists of glass corrosion products with much higher Zr and Ca, and lower Si and Na contents than the bulk glass. The hydroxylated layer thickness is about 2 mum after hydration at 55-degrees-C for one year.