Durability modelling of glass fibre reinforcement in cementitious environment

A main topic of consideration for glass-fibre reinforced cementitious composites is their durability. Recent developments of new cementitious matrices and advances in chemical composition and sizing of glass fibres lead to increased durability of cementitious composites with glass fibre reinforcement. Still, the relative importance of the main degradation mechanisms is not fully understood. A joint experimental program at RWTH-Aachen (Germany) and VUB-Brussels (Belgium) shows that the pH of the matrix has a considerable influence on the durability of the Studied composite. Recent investigations on single filaments in high alkalinity Solutions and on rovings in concrete show that filaments lose strength mainly due to chemical attack in local weak points of the glass structure. Once this chemical attack becomes diffusion controlled, further corrosion slows clown to a considerably lower rate. The aim of these investigations is to finally build a model, allowing prediction of the long-term behaviour of textiles - made of glass filaments - in concrete, which is based on the physico-chemical background of degradation. 1359-5997 (c) 2004 RILEM. All rights reserved.