Bearing capacity of steel fiber reinforced concrete flat slabs

The addition of steel fibers transforms the quasi-brittle non reinforced concrete into a ductile material with the ability to transfer stresses at high strain levels. As the accomplishment of a flat slab is one of the easiest techniques in building construction due to a simple formwork, lower costs due to reduced construction time are the consequence. These cost attenuations can be amplified with the use of steel fibers as only reinforcement because the time-consuming placement of the steel bars is omitted. In order to guarantee high rotation and simultaneously high bearing capacity the present research work foresees a dosage of 100 kg/m 3, which represents 1.3 % in volume. The aim of the thesis is to analyze the bearing capacity of steel fiber reinforced concrete flat slabs with corrugated steel fibers as the only reinforcement replacing the conventional steel bars. In the first three chapters an introduction on the state of the art in the fields of fiber concrete and at slabs is given. Experimental tests on small beams and square plates are achieved with the goal to obtain first information on the bearing behavior of the material. In order to obtain precise information on the failure mode and bearing behavior of SFRC at slabs, an experimental punching/bending test series on large scale plates with di erent diameters and slab thickness is achieved. It was found that the test specimens presented bending failure without the development of a characteristic punching cone. Further findings on segregation and a less strong fiber orientation in large scale elements compared to former research works are presented. The latter is used to develop a new suggestion concerning a geometrical factor proposed by most of the design codes.