At the 9th fib (International Concrete Federation) PhD Symposium in Civil Engineering, organized by the Karlsruhe Institute of Technology, I presented some of the experimental results of my research. Two years ago, I already participated in the 8th edition of this conference (in Copenhagen), and I enjoyed very much this conference which is aimed at concrete research. Very typical for these PhD symposia is that every speaker has 30 minutes: 20 minutes for the presentation and 10 minutes for questions. This scheme leaves much more room for discussion and interaction than your typical structural engineering conference.
The abstract of the paper is the following:
In slabs subjected to concentrated loads, the shear strength checks are conducted for two limit states: 1) shear over an effective width, and 2) punching shear on a perimeter around the point load. In cur-rent practice, the shear strength at the supports is determined with models that do not consider the transverse redistribution of load that occurs in slabs, which results in underpredictions for the actual slab shear capacity. Currently, an experimental program is being conducted at Delft University of Technology to determine the shear capacity of slabs under point loads near to the support. This paper presents the results of the tests conducted in continuous slabs and slab strips. In addition to studying the influence of the slab width, the specimens are tested with two types of reinforcement (ribbed and plain bars). The results of the experiments are compared to strength predictions from current design models. Also, recommendations for the support effective width and an enhancement factor for considering the effect of transverse load redistribution are given.
And here are the slides I used for the presentation: