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

Theodoros A Chrysanidis

doi:10.1186/s40069-019-0378-4

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.

Highlights

One issue of importance when it comes to the seismic architecture of buildings that have been developed using dual-reinforced concrete is the lateral stability of the given walls, when those, due to bending, mainly, overloading, face this risk
Cracks of small width are obvious for specimens with low degrees of tensile strain (10‰ and 20‰), while cracks of moderate and large width are present for specimens strained under larger elongation degrees (30‰ and 50‰)
5 Conclusions In this paper, five reinforced concrete column test specimens simulating the confined boundaries of seismic walls were tested to evaluate the structural performance in terms of the damage process, mode of failure and ultimate bearing load

Summary

Introduction

One issue of importance when it comes to the seismic architecture of buildings that have been developed using dual-reinforced concrete is the lateral stability of the given walls, when those, due to bending, mainly, overloading, face this risk. Deep penetration in the wall boundary parts’ yield region substantially augments slenderness, as they are subject, due to the Chrysanidis Int J Concr Struct Mater (2020) 14:3 when it comes to walls’ seismic mechanical properties. In specific, this has to do with walls’ transverse instability when put under significant pressure caused by a seismic episode. The main forms of damage, as seen on actual constructions in the reinforced concrete walls after the occurrence of seismic excitation, are reported in the literature (Penelis et al 1995; Penelis and Kappos 1996): 1.

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