ONE-WAY SLABS IN TRANSITION BETWEEN ONE-WAY SHEAR AND PUNCHING: EXPERIMENTS AND RECENT INSIGHTS FOR EVALUATION

Abstract

Bridge deck slabs are members on which one-way reinforced concrete slabs are found frequently loaded by concentrated loads. Although the one-way shear failure mechanism has gathered more attention in the past years, both one-way shear and two-way shear mechanisms may be critical for such loading conditions. This paper addressed the ultimate capacity of thin one-way reinforced concrete slabs subjected to concentrated loads and yielding of the flexural reinforcement. In practice, the test setup studied was devised to represent short-span rural bridges frequently found in Brazil. The experimental program included 12 tests performed on 6 slabs applying the concentrated loads at varied positions. All tests started to fail by punching shear. Nevertheless, both one-way shear and punching shear cracks were observed at ultimate states after shear redistribution. The reinforcement yielding followed by excessive flexural cracking hampered the arching action activation for loads closer to the support. The comparison of experimental and calculated resistances using standard code-based expressions suggests that improvements in unitary shear capacity could be supported as a result of slabs' transverse load distribution capacity. Alternatively, increasing the effective shear width can help estimate one-way shear capacity for loads near to the support.