Diagonally-Reinforced Concrete Coupling Beams with High-Strength Steel Bars
type: CreativeWork
description: The use of high-strength steel in diagonally reinforced coupling beams was investigated with the aims of minimizing reinforcement congestion and increasing the maximum permissible design shear stress without compromising behavior under large displacement reversals. Five large-scale diagonally reinforced concrete coupling beam specimens with clear span-to-depth ratios of 1.9 were tested under fully reversed cyclic loads. The primary variables were yield stress of the diagonal reinforcement (60 and 120 ksi [420 and 830 MPa]), target beam shear stress (10 and 15√(f_c^' ) psi [0.83 and 1.25√(f_c^' ) MPa]), length of the secondary (non-diagonal) longitudinal reinforcement, and axial restraint. All specimens had the same nominal concrete compressive strength and beam dimensions. Chord rotation capacities exhibited by the specimens with Grade 120 (830) reinforcement were between 5.1 and 5.6%, less than that of the control specimen with Grade 60 (420) diagonal reinforcement (7.1%). Neither development of secondary reinforcement nor increases in design shear stress affected specimen chord rotation capacity. The axially-restrained specimen with Grade 120 (830) diagonal reinforcement showed the same chord rotation capacity as a similar specimen without axial restraint, but 14% larger strength. In specimens with secondary longitudinal reinforcement extended into the wall (such that the embedment length exceeded the calculated development length), the localization of damage evident along the beam-wall interface in tests of specimens with bars terminating near the wall face was not observed. Although damage was more distributed throughout the beam span, deformation capacity was not increased. Among the specimens, it was shown that the initial stiffness, area of the shear force-chord rotation hysteresis cycles, and residual chord rotation at zero shear force changed in inverse proportion to the diagonal bar yield stress. A database of results from tests of diagonally reinforced co…
abstract: The use of high-strength steel in diagonally reinforced coupling beams was investigated with the aims of minimizing reinforcement congestion and increasing the maximum permissible design shear stress without compromising behavior under large displacement reversals. Five large-scale diagonally reinforced concrete coupling beam specimens with clear span-to-depth ratios of 1.9 were tested under fully reversed cyclic loads. The primary variables were yield stress of the diagonal reinforcement (60 and 120 ksi [420 and 830 MPa]), target beam shear stress (10 and 15√(f_c^' ) psi [0.83 and 1.25√(f_c^' ) MPa]), length of the secondary (non-diagonal) longitudinal reinforcement, and axial restraint. All specimens had the same nominal concrete compressive strength and beam dimensions. Chord rotation capacities exhibited by the specimens with Grade 120 (830) reinforcement were between 5.1 and 5.6%, less than that of the control specimen with Grade 60 (420) diagonal reinforcement (7.1%). Neither development of secondary reinforcement nor increases in design shear stress affected specimen chord rotation capacity. The axially-restrained specimen with Grade 120 (830) diagonal reinforcement showed the same chord rotation capacity as a similar specimen without axial restraint, but 14% larger strength. In specimens with secondary longitudinal reinforcement extended into the wall (such that the embedment length exceeded the calculated development length), the localization of damage evident along the beam-wall interface in tests of specimens with bars terminating near the wall face was not observed. Although damage was more distributed throughout the beam span, deformation capacity was not increased. Among the specimens, it was shown that the initial stiffness, area of the shear force-chord rotation hysteresis cycles, and residual chord rotation at zero shear force changed in inverse proportion to the diagonal bar yield stress. A database of results from tests of diagonally reinforced co…
author: Ameen, Shahedreen
language: en
keywords: Civil engineering, Coupling beam, earthquake resistant, high-strength steel, Reinforced concrete coupling beams
date published: 2019-05-31
date modified: 2026-07-24T02:46:40Z
provider: University of Kansas
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Kansas

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1808/29630