In-plane shear test of fibre reinforced concrete panels

The present paper concerns the investigation of polymer Fiber Reinforced Concrete (FRC) panels subjected to in-plane shear. The use of fibers as primary reinforcement in panels is a new application of fiber reinforcement, hence test methods, design bases and models are lacking. This paper contributes to the investigation of fibers as reinforcement in panels with experimental results and a consistent approach to material characterization and modeling. The proposed model draws on elements from the classical yield line theory of rigid, perfectly plastic materials and the theory of fracture mechanics. Model panels have been cast to investigate the correlation between the load bearing capacity and the amount of fibers (vol. %) in the mixture. The type of fibers in the mixture was Poly Vinyl Alcohol (PVA) fibers, length 8 mm, diameter 0.04 mm. The mechanical properties of the FRC have been determined from wedge splitting test (WST) specimens and compression cylinders. Three different test series were cast, where the only parameter which was varied was the amount of fibers in the mix, viz. 0.5, 1.0 and 1.5 vol. % fibers, respectively. Three identical experiments with panels were carried out in each series and the material was characterized with six WST. The dependence of the load-bearing capacity and the plasticity of the material on the fiber content were evident. Upper bound calculations were based on a simplification of the actual fracture pattern of each panel. Lower bound calculations were made by the use of a FEM program and reported elsewhere. From the experiments and the modeling it is shown that it is possible to predict the load bearing capacity of PFRC panels by the proposed approach.