INVESTIGATION ON INFLUENCE OF HINGE CONCRETE IN MESNAGER HINGE ON ITS MECHANICAL PROPERTY

Abstract

 Mesnager hinge is a concrete hinge composed of crossing reinforcing bar and hinge concrete. In Japanese seismic code, the compressive yield point of crossing reinforcing bars is defined as the ultimate state of Mesnager hinges and bending moment of Mesnager hinge is assumed to be small, because influence of hinge concrete in Mesnager hinge is not considered. However, Mesnager hinges commonly used in Japan have thick hinge concrete compared with conventional Mesnager hinges. Thus, this study investigated the results of cyclic loading tests for Mesnager hinges with thick hinge concrete carried out by our previous researches to evaluate the influence of hinge concrete in Mesnager hinge on its mechanical property. As a result, hinge concrete was found to enhanced the bending moment of Mesnager hinge. Additionally, crossing reinforcing bars were subject to tensile deformation due to hinge concrete. The observations contradict the assumption in Japanese seismic code. Therefore, two methods were proposed to calculate bending moment of Mesnager hinge and tensile yield point of crossing reinforcing bars. From results of numerical analysis with there methods, it is suggested that the proposed methods can evaluate the influence of hinge concrete in Mesnager hinge on its mechanical property.