Concrete Slabs under a Combination of Loads in Shear

Previous experimental research at Delft University of Technology indicated an increased shear capacity of slabs under concentrated loads as a function of decreasing distance to the adjacent line support. Expressions have been derived for this increase, including the definition of an appropriate effective width. However, it is unknown if the uniformly distributed loads on solid slab bridges, e.g. due to dead loads, that act over the full width can be combined with the effects of concentrated loads acting only over the associated effective width at the support. To study this problem, additional experiments have been carried out at Delft University of Technology, in which a combination of loads consisting of a concentrated load close to the support and a line load over the full slab width are applied. The experimental results prove that the superposition principle applies to combinations of concentrated loads and distributed loads.