Shear Strength of High Strength Concrete Beams Loaded Close to the Support

This paper deals with the analysis of the shear strength of reinforced concrete elements, with loads on the upper side near edge of the support. The reinforced concrete elements are designed according to EN 1992-1-1:2004. Results of the calculated shear strength are compared with the results of the experimental research of the reinforced concrete beams that were made of high-strength concrete and normal-strength concrete, comparatively. Analysis is related to the beams for which ratio between shear span (av), measured from the inner edge of the support, and effective depth of the cross-section (d), is smaller than 2.0. In that case, for design of the shear strength according to EN 1992-1-1:2004, provision that shear force should be reduced by the coefficient β=av/2d is prescribed. Results of the experimental research, in correlation with shear strength calculated according to EN 1992-1-1:2004, are being analyzed in this paper. It has been established that the proposed reduction gives a significantly reduced magnitude of the design value of the load, which do not provide the necessary safety of calculation.