Behavior of confined concrete beam by induced compression process

摘要

In order to provide higher mechanical effectiveness of confined concrete beam, the new technique proposed in this work consists to design at the ends of the steel reinforcements two opposing half cylindrical plates, creating an induced compression applied in the tended zone of the concrete beam element, when the steel reinforcement is subjected to tensile forces developed by the bending load. This technique ensures the concrete rigidity within the structure, avoids the problem of cracking and ruptures of the element and allows the transformation of the tensile force of the steel reinforcements into compressive force of the tended concrete inside the two half cylindrical plates. The confinement is induced by the displacement of the tended steel reinforcement, on all the transverse surface of the half-cylinder plates. This design avoids the penetration of the steel reinforcement in the concrete which generates a shear force of the section. Thus, the concrete of tended zone of the beam finds in position to take part in the resumption of the flexural efforts. The nonlinear finite element modeling shows that the proposed technique of confinement increases the strength and ductility of reinforced concrete beam. The numerical modelling analysis is completed by preliminary experimental work in order to allow for a better understanding of the behavior of this new confinement proposed technology.