Strength and deformability of externally strenghened reinforced concrete beams

Abstract. Purpose. The main objective was to determine experimentally the parameters of strength and stress - strain state of reinforced concrete beams reinforced with a new system of external tension members. Methodology. We consider the self-regulated, simple and reliable design of the new beams, which effectively enhanced by the action of an externalload on it through the rational redistribution of stresses between the compressed and stretched zones. In this amplification system comprises flexible elements which operate in tension. The proposed design solution adjustable-intense beam that contains a reinforced concrete body and tightness, fixed at both ends on the beam cooperating in the middle of a tension element, which rests on the lower face of the beam, and a transverse outer armature cooperating in near the support zones beam with the top and bottom of its facets and a middle portion engaged with tightening. Transverse reinforcement stretched, flexible, and mirror symmetrically located in areas near the support beams inclined to the longitudinal axis of the beam. Transverse reinforcement beam fixed at one end on the upper face of the beam closer to its center with limited displacement towards the middle, and at the other end on the lower edge of the beam closer to its supports restricted displacement to the supports and longitudinally stretching the upper face of thebeam and compressing the bottom thereof faces near the support compression and transverse zones. In the middle of the transverse reinforcement interacts with the tightening. Findings. The experimental study of strength and deformability of normal and reinforced concrete beams and girders, reinforced longitudinal-transverse external system; the results obtained after the experimental studies are not ordinary reinforced concrete beams and girders, reinforced longitudinal- transverse external system; the comparison of experimental results; determine the effectiveness of strengthening reinforced concrete beams longitudinal-transverse external system rebar.The results of experimental comparisons of the work load of bent reinforced concrete elements of self-regulation tightening with the conventional reinforced concrete beam. Originality. After tests it was found that reinforced beam БПС-ІІ withstood a load of 1,24 times greater and БПП-ІІ beam withstood a load of 1,16 times more than a regular bar. This reinforced beams were tougher for ordinary beam.