Research of strength of unaxial compressed concrete elements reinforced with FRP

Introduction. The possibility of FRP using in construction was considered back in the 1960s. The relevance of FRP using in concrete structures was associated with the need to increase the durability of road and marine structures. The widespread introduction and study was hindered by the lack of well-established industrial production of composite reinforcement until the 1980s. As of today, the Russian regulatory framework has a set of rules SP 295.1325800.2017 for the design of concrete structures reinforced with FRP. However, due to the insufficient study of the issue, in this set of rules, an approximate method is used to calculate the strength of unaxial compressed elements, which leads to an underestimation of the strength of unaxial compressed elements. This circumstance leads to an increase in the consumption of materials in the design of such structures. In this regard, it seems necessary to investigate the operation of unaxial compressed concrete elements reinforced with FRP and develop proposals for a refined methodology for calculating the strength of normal sections of such elements. Aim. Conduct experimental studies of the bearing capacity of normal sections of unaxial compressed concrete elements reinforced with FRP. Materials and methods. Experimental studies were carried out by testing of experimental concrete samples reinforced with FRP, with unaxial static compressive load. The research was carried out taking into account the requirements of the current regulations. Results. Experimental data on the strength of normal cross sections of unaxial compressed concrete elements reinforced with FRP have been obtained. Conclusions. According to the results of experimental studies, destructive loads were determined, crack formation patterns were established, and deflections of test samples were determined. During the tests, it was found that the experimental values of the destructive loads of the test samples are 15–32 % higher than their calculated values calculated according to the instructions of the current set of rules.