Evaluation of Out-of-Plane Response of R/C Structural Wall Boundary Edges Detailed with Maximum Code-Prescribed Longitudinal Reinforcement Ratio

Abstract

Abstract One type of failure of reinforced concrete seismic walls is out-of-plane buckling. This type of failure appears at the compressive cycle of loading during the cyclic seismic loading. This work is mainly experimental and tries to investigate the influence of the mechanical factor of tensile deformation on the behavior of seismic walls and particularly on the phenomenon of lateral buckling. Five test specimens are constructed simulating the confined boundary regions of structural walls. They are reinforced using the maximum longitudinal reinforcement ratio (4.02%) prescribed by modern seismic and concrete codes for boundary ends. Apart from the investigation of the factor of elongation degree, this method tries to examine if the detailing of walls using maximum allowable reinforced ratio for longitudinal reinforcement inhibits the appearance of transverse buckling. Each prism specimen was strained under different tensile deformation. Degrees of elongation used were equal to 0‰, 10‰, 20‰, 30‰ and 50‰. After the first tensile cycle of loading, a second compression loading cycle was applied on each specimen, till their failure. Thus, nine experiments were carried out in total-two for each specimen apart from the first specimen which suffered zero elongation. Empirical equations are derived trying to estimate the ultimate bearing capacity and the normalized axial deformation at failure for the different tensile degrees.

Keywords

• structural walls
• reinforced concrete
• lateral buckling
• confined boundaries
• tensile deformation
• reinforcement ratio