МЕТОДИКА РОЗРАХУНКУ ПІДСИЛЕННЯ ЗАЛІЗОБЕТОННИХ БАЛОЧНИХ ЕЛЕМЕНТІВ СИСТЕМОЮ КОМПОЗИТНИХ МАТЕРІАЛІВ

Abstract

The scientific work is devoted to the improvement of the calculation methodology of bending reinforced concrete beam elements strengthened with a system of composite materials (SCM) from carbon fiber. During the calculation based, on the limit state method, the recommendations of foreign standards (ACI 440.2R-02) were taken into account. The determination of the cross-sectional area of the external reinforcement was carried out by an iterative method, setting some initial value with subsequent adjustment based on the results of moment strength calculations. To prevent possible debonding of SCM from the concrete base, the coefficient ΚM, with which it is possible to limit the achievement of the limit value of tensile deformation (rupture) of carbon fiber, was introduced to the general calculation. Based on the results of the calculation, the necessary geometric parameters of the strengthening material (width, thickness, number of layers) were established, with the specified normative strength and modulus of elasticity, which allows to significantly increase the strength of the studied cross-section with full use of the external reinforcement system strength. The results of this research can be used in future during the design of structures joints strengthening with systems of composite materials based on carbon fibers, glass, aramid, etc.