Experimental Research Results of the Bearing Capacity of the Reinforced Concrete Beams Strengthened in the Compressed and Tensile Zones

Construction is one of the main factors determining the economic development of the state. Introduction of new technologies and materials at the strengthened and restored reinforced concrete structures allows to solve important questions of the building branch. The article describes the experimental research of the work of layers of reinforced concrete beams strengthened by the glued composites in the form of carbon fibers in the tensile zone, and steel fiber concrete in the compressed zone. Namely, tearing the band off in the area between the point of application of the force and the support occurred, when the maximum permissible load had been achieved. The work of the strengthening concrete and the concrete of the beams took place simultaneously without sudden change of deformation. The significant effect of the strengthening system was found in the strengthened beams. Under single load there was an increase of bearing capacity in beams strengthened with fine-grained concrete by 57%. In beams strengthened with steel-fiber concrete by 46%. At low-cycling load for beams strengthened by the fine-grained concrete the bearing capacity increased by 32%, and strengthened with steel-fiber concrete by 69%. For beams strengthened under the loading of fine-grained concrete by 66%, in the beams strengthened with steel-fiber concrete by 65%.