Study of Reinforced Concrete Beams with Indirect Reinforcement of Compressed Zone in the Form of Cross Welded Mesh

One of the design solutions, saving materials and increasing strength and deformation characteristics of concrete, is the use of indirect reinforcement. The volume of research devoted this problem for bending elements in comparison with compressed elements, is rather low. The aim of the research work is to analyze the influence of the indirect reinforcement on strength and deformation characteristics of the reinforced concrete beams. The test results of three batches of the beams with indirect reinforcement of compressed area in form of cross-welding mesh are given in the research work. Each batch consisted of the sample without mesh and two samples with various coefficients of the indirect reinforcement of compressed area. The batches were different from each other by the area of longitudinal reinforcement. The pattern change from brittle to plastic destruction of the samples was identified in the results of research. In this case, the limit deformability increases considerably with saving the high residual bearing capacity. We noticed that the influence of the indirect reinforcement on the beams work depends on not only coefficient of indirect reinforcement but also the area of longitudinal reinforcement. We explain it by growth of large deformation in concrete of the compressed area in the limit condition and, therefore, more effective inclusion of the indirect reinforcement. The bending reduction is 7.2-14.4% for the samples with mesh, the increase of the bending moment, satisfying the beginning of the concrete destruction of the compressed area, is 11-33%.