NUMERICAL AND FULL-SCALE EXPERIMENTS OF PRESTRESSED HYBRID REINFORCED CONCRETE-STEEL BEAMS

Recently, civil buildings are increasingly using composite reinforced concrete and steel (RCS) structures (beams, slabs, columns). Prestress in RCS structures has not yet found such a spread as, for example, in reinforced concrete and metal structures, although its use is known from technical sources. The present article is devoted to the evaluation of the stress-strain state of prestressed RCS beams. The procedure and results of computer modeling of the response of composite RCS beams consisting of steel I-beam, anchors, prestressed reinforcement and concrete are given. Two variants of arrangement of prestressed reinforcement are considered. According to the data of numerical studies, full-scale samples of beam models were made and their tests were carried out. The article presents the test procedure, the results of experimental studies in the form of graphs, diagrams. At the end of the article, analytical expressions are given for analysis of composite RCS beams of the described cross-section. Results of calculations, comparison of the results of numerical and full-scale experiments are presented. Subject: based on computer simulation and full-scale experiments, the stress-strain state of prestressed composite beams was investigated. Beams were studied with the arrangement of prestressed reinforcement along the I-beam flanges and along the envelope of the bending moment diagram. Research objectives: analyze the stress-strain state of beams, identify effectiveness of the arrangement of prestressed reinforcement. Materials and methods: for full-scale experiments, steel I-beams with lateral cavities filled with concrete were adopted, rod reinforcement was used as a prestressed reinforcement, and a dynamometric key was used for prestress (preload). ANSYS software package was used for computer modeling. Results: the computer simulation data of the stress-strain state of beams is obtained. The results are used for making full-scale samples. The obtained results of computer simulation are compared with the data of full-scale experiments. Conclusions: essential features of the response of prestressed composite beams are studied from numerical modeling, in-situ experiments and analytical calculations. The proposed calculation method gives a good match with the experimental data.