Monotonic Loading Tests of Ring-Beam Connections for Steel Reinforced Concrete Columns and RC Beams

et al. 2022

Structural Concrete

A joint system was proposed to connect square thin‐walled concrete‐filled steel tube (CFST) columns and reinforced concrete (RC) beams. In the system, longitudinal beam reinforcing bars are continuous through the joint zone by passing the rectangular holes in the steel tube, aiming to achieve direct load‐transfer of the beam and joint integrity; and the square thin‐walled steel tube with holes is strengthened by internal diaphragms. Previous cyclic tests showed that the proposed joint system satisfied the requirements of strong‐joint weak‐component, namely the shear capacity of the joint zone was larger than that provided by CFST columns and RC beams. However, further research was necessary to evaluate the behavior under axial compression, as the discontinuous diagonal ribs and holes in the joint steel tube weakened the load capacity. In this investigation, the effect of internal diaphragms was first evaluated based on the axial compression tests on six square CFST stub columns. The test results showed that the internal diaphragms effectively improved the strength and ductility. The finite element analyses (FEA) on square CFST columns and RC beam to CFST column joints stiffened by internal diaphragms were then carried out based on the verified FEA models. The analysis results showed that thicker internal diaphragms increased the strength, and changed the failure mode from the column‐center failure to column‐end failure for columns and from the joint failure to column failure for joints, respectively. Finally, the mechanics‐based models and axial strength equations of square CFST columns and RC beam to CFST column joints stiffened by internal diaphragms were proposed, and the predictions agreed well with the test and analysis results.

Section: Introductionmentioning

confidence: 99%

Axial compression behavior of reinforced concrete beam to square thin‐walled concrete‐filled steel tube column joints stiffened by internal diaphragms

Gan

Zhao

et al. 2022

Structural Concrete

“…A safe, reliable and convenient CFST column-RC beam joint is always a challenge for steel-concrete composite construction. Nie et al [6], Tang et al [7], Zhang et al [8], Pan et al [9] and Liao et al [10] experimentally investigated the monotonic and Zhou Z., Gan D., Zhou X.H. and Tan K.H.…”

Section: Introductionmentioning

confidence: 99%

Square reinforced CFST column to RC beam joint subjected to lateral loading: An investigation using finite element analysis

Gan

Proceedings 12th International Conference on Advances in Steel-Concrete Composite Structures - ASCCS 2018

et al. 2018

Concrete-filled steel tube (CFST) columns have been applied popularly in recent years, where they were connected with reinforced concrete (RC) beams or steel beams in a building. This paper proposes a joint system which connects the square reinforced concrete-filled thin-walled steel tube (RCFTWST) column and RC beam. In the joint system, reinforced bars are located in the square CFTWST column, and stiffeners are welded at adjacent sides of the square steel tube. Besides, the panel zone is strengthened by internal diaphragms. A finite element model (FEM) based on software ABAQUS was developed to evaluate the behavior of the proposed joint system under lateral loading, and parametric analysis was carried out. Based on the analysis results obtained from FEM, some important parameters were chosen. And two specimens were tested under combined axial compression and low-cyclic lateral load to assess the seismic performance of the proposed joint system. The axial load level was chosen as the parameter. Test results showed that all tested specimens performed well up to 5% drift and can satisfy the seismic requirements of “strong-joint weak-component”. In addition, the finite element model (FEM) is verified by comparing with the experimental results. The results can be well predicted by the model.

“…They also conducted experimental and analytical analysis on the seismic and post seismic behavior of this connection system. Lin et al [8] performed monotonic loading tests to examine the effectiveness and applicability of ring-beam connections for steel reinforced concrete (SRC) columns and RC beams. Wang et al [9] studied the experimental and analytical 3-D cyclic performances of a new ring beam connection between CFST Columns and RC beams.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Through-Beam Connection between CFST Column and RC Beam

Anupama

Mathew

Kumar

2016

AMM

The concrete filled steel tubular (CFST) columns consist of steel tube in-filled with concrete. The connections are the most important components of a CFST column and reinforced concrete beam structural system, since it combines the beams and the columns. In this paper, a through-beam ring connection for strengthening the joint between CFST column and RC beam is modeled using the finite element software package ANSYS and analysed the axial compressive behavior of the connection system. The numerical model is validated with the results available in the literature to confirm the structural efficiency of the ring beam connection system.