Structural behavior of reinforced concrete slabs subjected to uniform and concentrated loads
The load-bearing behavior of reinforced concrete slabs without stirrups subjected to concentrated loads is of national and international interest for research and practice. In particular, it has not yet been clarified whether a slab fails locally in the area of action, i.e. punching, or as a normal shear failure. Depending on this, the influence of a uniform load has to be clarified.In most experimental investigations of reinforced concrete slabs, the concentrated load was located close to the support, as failure was assumed to occur in this region. However, a series of experiments carried out by the applicant as part of a research project funded by the DFG showed that the shear failure occurs close to the load application, which contradicts the common opinion. The developed new design approach has been included in a German regulation. However, some questions remain unanswered. For example, the influence of the flexural reinforcement on the load-bearing capacity has not yet been sufficiently experimentally verified. In the aforementioned research project, the degree of reinforcement was reduced from ρ_l = 1,16 % to ρ_l = 0,71 % in one experiment, whereby the failure loads hardly changed. The influence of the reinforcement on the load-bearing behaviour is treated differently in various analytical approaches. In a real slab, concentrated loads always act together with uniform loads. The influence of additional uniform and line loads on the load-bearing behaviour of reinforced concrete slabs is to be investigated. Large-scale tests on cantilevered reinforced concrete slabs and numerical analyses are conducted for both topics.