Železobetonové nosníky bez smykové výztuže

Abstract

The theme of the diploma thesis is the experiments of reinforced concrete beams without shear reinforcement and the determination of the mechanical properties of three different mixtures based on the same ingredients. The first mixture was a referential one in which the binder was ordinary Portland cement. In the second mix, cement was replaced, and an alkali-activated binder was used instead. In the third mixture, part of the aggregate was replaced with light artificial aggregate. The theoretical part dealt with a brief description of the information about concrete, its primary components, types, designing and typical testing methods. The practical part focused on testing and mutual comparison, firstly of processability of the fresh mixture and then of mechanical characteristics, which include strength in compression, split tensile strength or modulus of elasticity. In addition, tests of resistance to unfavourable temperatures and resistance to frost and defrosting chemicals. The structural elements are reinforced concrete beams without shear reinforcement, while 3 degrees of reinforcement were used for each variant of the mixture and were tested with a three-point bend test. The last test was the determination of the tear strength of the surface layer of the beams.