Title:
Reinforced Concrete Coupling Beams with High-Strength Steel Bars
Author(s):
Alexander S. Weber-Kamin;Shahedreen Ameen;Rémy D. Lequesne;Andrés Lepage
Publication:
CRC
Volume:
Issue:
Appears on pages(s):
Keywords:
high-strength,reinforced,concrete,coupling,beams
DOI:
Date:
1/23/2020
Abstract:
The use of high-strength steel bars in reinforced concrete coupling beams is expected to
reduce reinforcement congestion. A series of tests was conducted to investigate the effects of
high-strength reinforcement on coupling beam behavior. This document summarizes the test
program and test data.
Eleven large-scale coupling beam specimens were tested under fully reversed cyclic
displacements of increasing magnitude. The main variables of the test program included: yield
stress of the primary longitudinal reinforcement (Grade 80, 100, and 120 [550, 690, and 830]),
span-to-depth (aspect) ratio (1.5, 2.5, and 3.5), and layout of the primary longitudinal
reinforcement (diagonal [D] and parallel [P]). All beams had the same nominal concrete
compressive strength (8,000 psi [55 MPa]) and cross-sectional dimensions (12 by 18 in. [310 by
460 mm]). Beams were designed for target shear stresses of 8ඥ𝑓
ᇱ psi (0.67ඥ𝑓
ᇱ
MPa) for D-type
beams and 6ඥ𝑓
ᇱ psi (0.5ඥ𝑓
ᇱ MPa) for P-type beams. Transverse reinforcement was Grade 80
(550) in all but one beam, which had Grade 120 (830) reinforcement.
The test program is documented by presenting the details of specimen construction, test
setup, instrumentation, and loading protocol. Documentation of test data includes material
properties, cyclic force-deformation response, progression of damage, calculated and measured
strengths, initial stiffness, and measured reinforcement strains.