CAPACITY OF REINFORCED CONCRETE ONE-WAY SLABS UNDER CONCENTRATED LOADS

For the assessment of existing reinforced concrete slab bridges, the shear capacity under concentrated loads and transition to flexural failure are under discussion. Previous research showed an increased shear capacity for slabs under concentrated loads close to the support, so that for assessment, positions farther from the support became governing. This experimental research studies the flexural and shear capacity of reinforced concrete slabs under concentrated loads. For this purpose, six slabs representing 1:2 scale continuous slab bridges were tested at various positions from the support and along the width. The results show two main failure modes: flexural failure (onset of yielding of the reinforcement), and shear failure. Secondary punching was observed as well. The comparison between the test results and calculations methods shows that all considered methods perform reasonably well when both shear and flexure are considered, and the effective width in shear is included, with average tested-to-predicted capacities between 0.92 (Regan’s method) and 1.39 (Extended Strip Model) and coefficients of variation between 15% (Regan’s method) and 25% (ACI 318-19 and Eurocode 2). These insights can be used for the assessment of existing reinforced concrete slab bridges.