Stress-strain modelling for a composite reinforced concrete beam

Abstract

The study is aimed at the features of modeling the stress-strain state of a concrete beam, reinforced with two types of fibrous composites. The necessity of strengthening existing reinforced concrete structures can be caused by the reconstruction or technical re-equipment, which often entails an increase in the load on the load-bearing structures of buildings and facilities, as well as during the elimination of the consequences of factors that led to a decrease in the bearing capacity or a failure of loadbearing structures. In order to study the applicability of the model, we analysed the results, obtained during bending and axial compression tests of T-section reinforced concrete beam specimens with welded frame reinforcement that were in operation and the results of a numerical study in a LIRA software suite. The stress-strain state of specimens was modelled in a nonlinear formulation using the finite element method. The conducted analysis and theoretical studies have shown the applicability of models, developed based on a limited test database, unclear, especially with regard to a wide range of compression coefficients, while the results of modeling the behavior of reinforced concrete beams have demonstrated sufficient accuracy for applying in the strengthening design using external composite reinforcement.