Composite RCS joint designs for circular high-strength reinforced concrete columns
Journal
Journal of Building Engineering
Journal Volume
104
Start Page
112233
ISSN
2352-7102
Date Issued
2025-06-15
Author(s)
Abstract
This study presents the development and testing of three novel beam-column joint designs for Reinforced Concrete column and Steel beam (RCS) systems, specifically tailored for circular columns. The existing research primarily dealt with RCS joints having square/rectangular columns and conventional steel reinforcement (fy≤ 490 MPa). However, circular columns, often necessitated by architectural requirements, pose a nuanced design challenge not thoroughly covered in existing literature. The proposed joint details utilize high-strength concrete (fc′ = 82.7 MPa) and high-strength deformed bars (fy = 690 MPa) in the columns. Design guidelines were established for estimating joint strength and proportioning the additional attachments used in the joint detail. Large-scale experimental testing was conducted to validate the efficacy of the proposed joints, assessing failure mechanisms, hysteretic and deformation responses, and scrutinizing strain development in structural components. All tested specimens exhibited stable and ductile behavior, achieving the desired beam-hinging mechanism with minimal joint and column damage. However, the bolted web-welded flange splice detail, commonly used in Taiwanese construction, displayed excessive bolt slippage, leading to weld fracture in one specimen. Further, the study demonstrated that the minimum joint depth provisions of the Taiwan New-RC draft could be safely extended to the proposed joints. Furthermore, due to the additional confinement provided by the steel beam and face-bearing plates, the proposed designs allow for a reduction in joint confinement reinforcement compared to the requirements of ACI-318. Finally, the analytical approach developed for estimating joint strength was found to be conservative and suitable for design purposes.
Subjects
Beam-column joint
CFT joint
Composite structure
High-strength steel
Moment frame
Seismic behaviour
Through-beam joint
SDGs
Publisher
Elsevier BV
Type
journal article