EXPERIMENTAL STUDY REGARDING DEFLECTION IN SHEAR OF HIGH STRENGTH CONCRETE BEAMS

Shear failure of concrete elements is nearly always brittle and occurs with virtually no warning in terms of vertical deflections. This behavior is amplified when the strength of the concrete used to cast said concrete elements is high. This joining of a brittle type of failure and a material recognized for sudden and explosive failures requires investigation in order to give structural engineers, looking to use such elements, the knowledge necessary to build safe structures, utilizing the advantages that a high strength concrete brings, such as reduced cross-sections and very high durability. In order to study the deflections of high strength concrete beams subjected to concentrated loads near to the supports 24 experimental tests were performed on high strength concrete beams cast with concrete which had a compressive strength corresponding to concrete class C80/90 according to Eurocode 2. The steel used for reinforcement was S500 steel, and the stirrups used were placed at 3 different intervals in order to evaluate the effect of the quantity of transverse reinforcement on the deflections of the beams. This paper presents the experimental results obtained from the tests mentioned above and discusses the influence of the variable parameters in the study on the behavior of high strength concrete beams tested in shear generated by concentrated loads near their supports.