Experimental and numerical study of punching shear response of pedestrian bridge fibre reinforced concrete slabs

Abstract

This study is a part of the ongoing project, which aims to develop an innovative stress-ribbon pedestrian bridge structure that comprises fibre reinforced concrete (FRC) deck adhesively joined to the ribbon bands made of carbon fibre reinforced polymer (CFRP). The objectives of the project are to increase the corrosion resistance and service life of the system by replacing structural steel with CFRP sheets and synthetic fibres, to reduce the deck thickness by applying polymer fibres instead of conventional steel reinforcement and to increase stiffness of the stress-ribbon system by forming a composite connection between the main load-resisting elements of the bridge. This work presents the results of an experimental and numerical investigation of load bearing capacity of the FRC slabs developed for the bridge prototype. The alternative slab specimens (having different thickness) were subjected to concentrated load. The study is focused on the punching shear resistance of the specimens. Four 1000×800 mm deck segments were produced. The thickness of the segments has varied from 30 mm to 50 mm. The segments were simply supported and tested up to failure under monotonic concentrated load acting on the centre of the slab over a contact area of 100×100 mm. This load simulates the footprint of sustained truck wheel load. None of the segments failed in punching shear. A nonlinear finite element (FE) model was developed to represent the shear resistance of the FRC slab segment. The accuracy of the FE model was verified by using the test results. The gathered results have demonstrated that the punching shear resistance of all considered slab segments (without conventional bar reinforcement) is sufficient and the FRC slab of 30 mm thickness is applicable for composing the pedestrian bridge decks.