scholarly journals Mechanical behaviour of precast prestressed reinforced concrete beam–column joints in elevated station platforms subjected to vertical cyclic loading

2021 ◽  
Vol 60 (1) ◽  
pp. 818-838
Author(s):  
Haiou Shi ◽  
Jinxia Zhao ◽  
Fangmu Chen ◽  
Junjin Lin ◽  
Jianhe Xie
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Mechanical Performance ◽  
Reinforced Concrete Beam ◽  
Lessons Learned ◽  
Urban Rail Transit ◽  
Rc Structures ◽  
Seismic Loadings ◽  
Column Joint ◽  
Energy Dissipation Capacity

Abstract Precast-reinforced concrete (RC) structures in urban rail transit projects can provide many advantages over their cast-in-place counterparts. However, lessons learned from past earthquakes show that beam-column joints may be a critical point of these structures and can overestimate the mechanical performance under vertical seismic loadings if not properly understood. This paper presents unbonded and bonded prestressed precast RC beam-column joints for elevated station platforms. Prestressed steel strands are used to provide joints with self-centring capacity. The performance of the proposed joints under vertical cyclic loadings is experimentally investigated and compared to that of monolithic joints in this study. The obtained results demonstrate the good properties of the proposed precast joints in terms of bearing capacity, energy dissipation capacity and ductility control. A comparison with a conventional monolithic beam-column joint indicates the better performance against earthquakes of the proposed precast prestressed joints, and the precast joint with symmetric prestressed steel strands in the top and bottom of the beam exhibits better flexural stiffness and energy dissipation capacity.

Seismic Rehabilitation of Beam-Column Joints Using FRP Sheets and Buckling Restrained Braces

2013 ◽  
Vol 479-480 ◽  
pp. 1170-1174
Author(s):  
Hee Cheul Kim ◽  
Dae Jin Kim ◽  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Performance ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Seismic Rehabilitation ◽  
Buckling Restrained Braces ◽  
Column Joint ◽  
Energy Dissipation Capacity

The purpose of this study was to evaluate seismic performance of rehabilitated beam-column joint using FRP sheets and Buckling Restrained Braces (BRBs) and provide test data related to rehabilitated beam-column joints in reinforced concrete structures. The seismic performance of total six beam-column specimens is evaluated under cyclic loadings in terms of shear strength, effective stiffness, energy dissipation and ductility. The test results showed wrapping FRP sheets can contribute to increase the effect of confinement and the crack delay. Also retrofitting buckling restrained braces (BRBs) can improve the stiffness and energy dissipation capacity. Both FRP sheets and BRBs can effectively improve the strength, stiffness and ductility of seismically deficient beam-column joints.

scholarly journals Novel Ductile Enhancement in the Structural Characteristics of External Beam Column Joint with Potassium Activated Green Concrete Technology: An Artistic Establishment of Seismic Challenging Structures

2021 ◽  
Author(s):  
Mohana R
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Structural Characteristics ◽  
Concrete Specimen ◽  
Concrete Technology ◽  
Finite Element Software ◽  
Drift Ratio ◽  
Joint Application ◽  
Column Joint ◽  
Energy Dissipation Capacity

Abstract Ductility and energy dissipation capacity of the beam column joints are the two prominent characteristics which governs the stability of the entire structure constructed in the seismic prone areas. In this paper, the effect of potassium activated geopolymer concrete in the exterior beam column joint application is investigated under low frequency cyclic loading. Numerical analysis has been done by using the finite element software Abaqus and compared with the experimental work. From the load deformation relationship, parametric studies are carried out in the aspects of ductility, stiffness degradation, energy dissipation capacity, drift ratio and cracking pattern. The use of potassium activated geopolymer technology in the exterior beam column joint application resulted in the improved ductility, energy dissipation capacity with superior ultimate load carrying capacity of 1.05% over conventional cement reinforced concrete beam column joints with special confining reinforcement confirmed by IS 13920 due to the enormous polymerisation activated by high molecular potassium ions.2.78% improved energy dissipation capacity of potassium based geopolymer specimen resulted in the lesser number of non structural cracks and 11.26% more deformation under 11.96% enlarged drift ratio than the conventional reinforced concrete specimen. From the observed results it is clearly noted that the implementation potassium activated green polymer technology in the beam column joints possessed enhanced ductility characteristics to protect the structure susceptible to seismic environment and resulted in the innovative, economical and sustainable mode of seismic resistant building construction.

Cyclic Loading Behavior of Weak Reinforced Concrete Beam-Column Connections

2008 ◽  
Vol 400-402 ◽  
pp. 881-886 ◽  
Author(s):  
Li Xue Jiang ◽  
Shi Ju Zheng ◽  
Wei Ping Zhang ◽  
Xiang Lin Gu
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Behavior ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Transverse Reinforcement ◽  
Negative Moment ◽  
Energy Dissipation Capacity ◽  
Joint Shear ◽  
The One

Eight weak reinforced concrete beam-column connections and two strong ones subjected to cyclic loads were tested. Effects of the one-way slab, top reinforcement ratio of the beam as well as the transverse reinforcement ratio inside the joint on the seismic behavior of reinforced concrete beam-column connections were primarily investigated. Tests results show that, when subjected to the negative moment, the beam flexural resistance increases notably due to the presence of the slab. However, failure mode of the weak connection transforms from the beam flexural failure to the joint shear failure, resulting from the increased joint shear brought by the slab participation. Besides, the presence of the slab reduces the ultimate relative rotation, ductility and energy-dissipation capacity of the connection. Generally, weak connections can receive more benefit from the one-way slab than strong connections. Connections with less amount of top reinforcement in the beam exhibit better ductility and energy-dissipation capacity, which indicates that it is not always good to strengthen the beam negative moment zones in existing structures. The transverse reinforcement inside the joint has little effect on the seismic behavior of the weak connection with a one-way slab.

scholarly journals Equivalent Viscous Damping Ratio Model for Flexure Critical Reinforced Concrete Columns

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Qin Zhang ◽  
Zong-yan Wei ◽  
Jin-xin Gong ◽  
Ping Yu ◽  
Yan-qing Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Damping Ratio ◽  
Hysteretic Behavior ◽  
Viscous Damping ◽  
Ratio Model ◽  
Rc Columns ◽  
Equivalent Viscous Damping ◽  
Rc Structures ◽  
Energy Dissipation Capacity

In order to determine the energy dissipation capacity of flexure critical reinforced concrete (RC) columns reasonably, an expression for describing the hysteretic behavior including loading and unloading characteristics of flexure critical RC columns is presented, and then, a new equivalent viscous damping (EVD) ratio model including its simplified format, which is interpreted as a function of a displacement ductility factor and a ratio of secant stiffness to yield stiffness of columns, is developed based on the proposed hysteretic loop expression and experimental data from the PEER column database. To illustrate the application of the proposed equivalent damping ratio model, a case study of pushover analysis on a flexure critical RC bridge with a single-column pier is provided. The analytical results are also compared with the results obtained by other models, which indicate that the proposed model is more general and rational in predicting energy dissipation capacity of flexure critical RC structures subjected to earthquake excitations.

Deformation Characteristics of Reinforced Concrete Beam-Column Joint Cores under Earthquake Loading

2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian
Keyword(s):  
Reinforced Concrete ◽  
Shear Deformation ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Frame ◽  
Bond Failure ◽  
Strain Compatibility ◽  
Concrete Frame ◽  
Column Joint ◽  
Reinforced Concrete Frame Structures

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.

A combined experimental and numerical analysis on the seismic behavior of short reinforced concrete columns with different structural sizes and axial compression ratios

2017 ◽  
Vol 27 (9) ◽  
pp. 1416-1447 ◽  
Author(s):  
Liu Jin ◽  
Shuai Zhang ◽  
Dong Li ◽  
Haibin Xu ◽  
Xiuli Du ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Axial Compression ◽  
Seismic Behavior ◽  
Load Capacity ◽  
Concrete Columns ◽  
Simulation Method ◽  
Reinforced Concrete Columns ◽  
Mesoscopic Simulation ◽  
Energy Dissipation Capacity

The results of an experimental program on eight short reinforced concrete columns having different structural sizes and axial compression ratios subjected to monotonic/cyclic lateral loading were reported. A 3D mesoscopic simulation method for the analysis of mechanical properties of reinforced concrete members was established, and then it was utilized as an important supplement and extension of the traditional experimental method. Lots of numerical trials, based on the restricted experimental results and the proposed 3D mesoscopic simulation method, were carried out to sufficiently evaluate the seismic performances of short reinforced concrete columns with different structural sizes and axial compression ratios. The test results indicate that (1) the failure pattern of reinforced concrete columns can be significantly affected by the shear-span ratio; (2) increasing the axial compression ratio could improve the load capacity of the reinforced concrete column, but the deformation capacity would be restricted and the failure mode would be more brittle, consequently the energy dissipation capacity could be deteriorated; and (3) the load capacity, the displacement ductility, and the energy dissipation capacity of the short reinforced concrete columns all exhibit clear size effect, namely, the size effect could significantly affect the seismic behavior of reinforced concrete columns.

scholarly journals THE STATE OF THE ART OF THE STUDIES ON THE REINFORCED CONCRETE BEAM TO COLUMN JOINT

1981 ◽  
Vol 19 (9) ◽  
pp. 3-15
Author(s):  
Koichiro Ogura ◽  
Masataka Sekine
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
State Of The Art ◽  
Reinforced Concrete Beam ◽  
The State ◽  
Column Joint
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