Modelling of the splitting failure mode in textile-reinforced concrete

Abstract

The bond behaviour of fibre reinforced polymer (FRP) textile-reinforced concrete (TRC) can differ significantly from ordinary steel-reinforced concrete. Furthermore, some textile fabrics tend to induce a splitting crack in the layer of the textile reinforcement, which may lead to spalling of the concrete cover. The question therefore arises as to whether the concrete cover affects the splitting failure mode. To analyse this behaviour, upper and lower bounds on the tensile splitting resistance are estab-lished. The fibre strands of textile reinforcement often have an elliptical cross-sectional geometry, with the minor ellipse axis oriented perpendicular to the layer of the textile reinforcement. This leads to a non-uniform distribution of the splitting stresses. The governing fibre-strand is subsequently idealised using two circular cross-sections, with a radius equal to the larger ellipse axis (upper bound) or the minor ellipse axis (lower bound). By applying Tepfers partly cracked elastic bond model, the splitting-crack resistance can be calculated for each case. By comparing the two theoretical bounds for typical roving geometries in TRC structures, it is noted that failure is mainly controlled by a splitting crack in the layer of the textile reinforcement.