Dauerhaftigkeit von textilen Glasfaserbewehrungen im Beton

A decrease of strength in AR-glass fibres embedded in cementitious concrete is usually found after a long period. Contrary to obviously given explanations this behaviour cannot be explained by a destroying corrosion of the glass body. The obtained alterations are essentially described by two different processes. The polymeric protective coating material (sizing) on the glass fibre surface is at least partly decomposed on the one hand. A clearly marked growth of crystalline products caused by the hydration process on the other hand forms film- or shell-like wraps on the filament surface changing at least in parts the stiffness of the filaments and leading to an embrittlement and a reduced crack bridging capability. In the paper the decrease of sizing is estimated and also the behaviour of fibre-matrix-bond is examined.