scholarly journals Experimental and numerical study of temperature developments of composite joints between concrete-encased concrete-filled steel tube columns and reinforced concrete beams

2020 ◽  
Vol 116 ◽  
pp. 103187
Author(s):  
Kan Zhou ◽  
Lin-Hai Han
2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.


2020 ◽  
Vol 23 (13) ◽  
pp. 2866-2881
Author(s):  
Longji Dang ◽  
Shuting Liang ◽  
Xiaojun Zhu ◽  
Jian Yang ◽  
Yamin Song

This article presents a staggered and out-of-plane connection between concrete-filled steel tubular column and reinforced concrete beam (SOC-TCB). SOC-TCB is taken from the basement roof joint of Suning center, which is a height of 341.85 m in China. In this joint system, the H-shaped steel brackets are welded with steel tube to transfer shear and moment. Moreover, the reinforcing bars are interrupted by steel tube and lapped with steel bracket. To investigate the seismic behavior of SOC-TCB, four types of SOC-TCBs were tested under reversal cyclic loading. The differences between specimens were staggered height and out-of-plane angle. Seismic performance was evaluated based on hysteretic behavior, failure mode, shear deformation, rotational deformation, and energy dissipation. The results showed that the shear deformation of joints was extremely small and the plastic hinges were formed at reinforced concrete beams. Due to insufficient anchorage length of longitudinal bars, anchoring failure was found in the reinforced concrete beams. However, SOC-TCB showed better seismic behavior as long as sufficient anchorage of longitudinal bars was ensured.


2020 ◽  
Vol 857 ◽  
pp. 120-129
Author(s):  
Abdul Muttalib I. Said ◽  
Qais H. Al-Shemmari

The numerical investigations were carried out to study the behavior of reinforced concrete beams strengthened by CFRP under different loading conditions (pure bending and combined bending and torsion). The numerical work included analysis of eight experimentally tested beams of rectangular cross-section dimensions of (160×240) mm and (2600) mm length keeping the area of the ordinary reinforcement constant for all beams. The following parameters were taken into consideration, twisting to bending moment ratio (T/M) and CFRP strengthening arrangement. The analyzed beams are divided into four groups. Each group consists of two beams; the first beam is without CFRP strengthening, the other beam is strengthened with CFRP. Each beam is loaded to a different loading conditions (pure bending, T/M=0.5, T/M=1.0, T/M=2.0). The CFRP sheets were attached externally to the beam. Analysis results were analyzed based on influence of CFRP on ultimate load and vertical mid-span deflection. According to the numerical study, it was found that all strengthening arrangements of CFRP sheets exhibited a significant increase in ultimate strength. The three-dimensional (3D) finite element model (FEM) utilized in present work is capable to simulate the behavior of externally strengthened reinforced concrete beams by CFRP. Full bond connections (no slip) are assumed between the CFRP sheets and surface of concrete. The comparison between the numerical and the experimental results declared the validity of the numerical analysis where the range of the (Pexp./PANSYS) ratio in ultimate load was from 0.847 to 1.157. The general behavior of the (FEM) shows good agreement with the test results from the experimentally tested beams.


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