UTILIZATION OF STEEL FIBERS IN DIAGONALLY REINFORCED CONCRETE COUPLING BEAMS AS ADDITIONAL TRANSVERSE REINFORCEMENTS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Hyun-Do Yun ◽  
Seok-Joon Jang ◽  
Sun-Woo Kim ◽  
Wan-Shin Park
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Reinforced Concrete Beam ◽  
Steel Fibers ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Structural Walls ◽  
Cyclic Shear ◽  
Double Curvature ◽  
Structural Behaviors

The purpose of this study is to investigate the feasibility of using hooked-end steel fibers as additional transverse reinforcements such as cross ties and leg bars for diagonally reinforced concrete (DRC) coupling beams aligned vertically over coupled special structural walls. Three 1/3-scale short beams were made and tested under cyclic shear in a double curvature condition. All specimens have the same reinforcement configuration except for transverse reinforcing details and the clear span length-to-section depth ratio (lnh) of 2.0. Reinforced concrete (RC) coupling beam (RC-CB) was designed with full confinement of diagonally reinforced concrete beam section based on the seismic design provisions of the ACI 318-14 Code. To improve the constructability without sacrificing strength and ductility, the fiber contents in the FRC0.75-CB and FRC1.50-CB specimens replacing additional transverse bars with steel fibers were 0.75% and 1.50% at volume fraction, respectively. Test results revealed that additional transverse reinforcement in the diagonally reinforced coupling beams have a significant effect on the cracking and structural behaviors. For diagonally reinforced coupling beams with only hoops and without crossties and legs of hoop, the addition of steel fiber at volume fraction of more than 0.75% to concrete provides equal cracking and structural behaviors as compared to those of diagonally reinforced coupling beam with full confinement details.

scholarly journals Hysteretic Behavior of Reinforced Concrete Coupling Beams According to Volume Fraction of Steel Fiber

2020 ◽  
Vol 13 (1) ◽  
pp. 182
Author(s):  
Joo-Hong Chung ◽  
Dong-Hee Son ◽  
Su-Yong Kim ◽  
Baek-Il Bae ◽  
Chang-Sik Choi
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Hysteretic Behavior ◽  
Steel Fiber Reinforced Concrete ◽  
Coupling Beams ◽  
Cyclic Loading Tests

The purpose of this study was to evaluate the structural performance of steel fiber reinforced concrete (SFRC) coupling beams. Reversed cyclic loading tests were performed with full-scale specimens. The main variable for the tests was the volume fraction ratio of the steel fibers. The results showed that the maximum strength was increased by about 11% with 1% of steel fibers incorporated, and about 24% when the ratio of mixed fibers was doubled to 2%. Because numerous microcracks occurred, decreased crack width due to the bridge effect was observed with the steel fiber reinforcement. Increased diagonal tension crack angles and energy dissipation also appeared as the volume fraction of steel fibers increased. The contribution of shear to the total deformation was decreased while the contribution of rocking was increased as steel fibers were added. Considering the results of these experiments, it can be concluded that steel fiber reinforcement affects the deformation of coupling beams in various ways, and should be considered when estimating the effective stiffness of such beams when SFRC is introduced.

scholarly journals Scaled Approach to Designing the Minimum Hybrid Reinforcement of Concrete Beams

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5166
Author(s):  
Andrea Gorino ◽  
Alessandro Fantilli
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Volume Fraction ◽  
Testing Procedure ◽  
Reinforced Concrete Beam ◽  
Fiber Reinforced Concrete ◽  
Scale Model ◽  
Fiber Volume ◽  
Technical Literature

To study the brittle/ductile behavior of concrete beams reinforced with low amounts of rebar and fibers, a new multi-scale model is presented. It is used to predict the flexural response of an ideal Hybrid Reinforced Concrete (HRC) beam in bending, and it is validated with the results of a specific experimental campaign, and some tests available in the technical literature. Both the numerical and the experimental measurements define a linear relationship between the amount of reinforcement and the Ductility Index (DI). The latter is a non-dimensional function depending on the difference between the ultimate load and the effective cracking load of a concrete beam. As a result, a new design-by-testing procedure can be established to determine the minimum reinforcement of HRC elements. It corresponds to DI = 0, and can be considered as a linear combination of the minimum area of rebar (of the same reinforced concrete beam) and the minimum fiber volume fraction (of the same fiber-reinforced concrete beam), respectively.

Considerations on Using the Strut and Tie Method for Modelling Coupling Beams

2017 ◽  
Vol 21 ◽  
pp. 116-121
Author(s):  
Vasile Murăraşu ◽  
Vasile Mircea Venghiac
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Linear Analysis ◽  
Numerical Analyses ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Structural Walls ◽  
Element Analysis ◽  
Linear Elastic ◽  
Strut And Tie

This paper presents a synthesis of the numerical analyses regarding the method of modelling the coupling beams of structural walls. The directions of the struts and ties are established according to the results obtained after a linear-elastic finite element analysis. The results obtained after modelling using the Strut and Tie Method, with the struts and ties oriented along the diagonals of the coupling beam, coincide with the results obtained by applying the theory provided by EC8, which proves the viability of the method. This is also confirmed by the results obtained after a non-linear analysis was carried out in the LUSAS finite element environment.

Analysis on the Ductility Performance of Reinforced Concrete Coupling Beams in Shear Wall Structure

2013 ◽  
Vol 788 ◽  
pp. 538-541
Author(s):  
Peng Zhang ◽  
Fu Ma
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Strength ◽  
Shear Wall ◽  
Wall Structure ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Element Analysis ◽  
Reinforcement Scheme

Coupling beam, the first line resisting earthquake, is directly related to the overall performance of the shear wall structure. Using the large general finite element analysis software ANSYS, the coupling beam span-depth ratio is 2~3 different reinforcement scheme in finite element analysis. Analysis on the ductility performance of reinforced concrete coupling beams in shear wall structure in three fields: the concrete strength grade, the longitudinal reinforcement ratio and the stirrup ratio, provides a basis for the design of the structure and to provide a reference for similar studies.

scholarly journals Cracking Propagation and Pattern Behaviour of Irregular-Shaped Polyethylene Terephthalate Fibre Reinforced Concrete Beam

2015 ◽  
Vol 773-774 ◽  
pp. 911-915 ◽  
Author(s):  
J.M. Irwan ◽  
R.M. Asyraf ◽  
N. Othman ◽  
H.B. Koh ◽  
A.K. Aeslina ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Polyethylene Terephthalate ◽  
Concrete Beam ◽  
Volume Fraction ◽  
Reinforced Concrete Beam ◽  
Rc Beam ◽  
Materials Properties ◽  
Tensile Strength Test ◽  
Structural Test ◽  
Polyethylene Terephthalate Fibre

This paper reports the results on cracking propagation and pattern of reinforced concrete (RC) beam conducted using irregular-shaped Polyethylene Terephthalate (IPET) as a fibre. Three volume fraction of IPET fibre is used namely, 0.5%, 1% and 1.5%. All RC beam specimens are tested under four point loading under flexural capacity behaviour. Prior to structural test, the materials properties which include the compressive and tensile strength test and modulus of elasticity test were determined. The results than are compared with control RC beam. It is found that the RC beam with IPET fibre does not significantly change the behaviour of failure mode, cracking propagation and pattern compared to control RC beam.

Nonlinear seismic response predictions of walls coupled with steel and concrete beams

1998 ◽  
Vol 25 (5) ◽  
pp. 803-818 ◽  
Author(s):  
Kent A Harries ◽  
Denis Mitchell ◽  
Richard G Redwood ◽  
William D Cook
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Dynamic ◽  
Steel Beams ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Coupled Wall ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Steel Coupling Beam ◽  
Steel Coupling Beams

The design and nonlinear dynamic analyses of four coupled wall prototype structures are presented. Two ductile partially coupled and two ductile coupled wall structures are considered, each having reinforced concrete and steel coupling beams. The design of each of the prototype structures was based on the provisions of the 1995 National Building Code of Canada. Nonlinear dynamic analyses of each structure, using four different scaled earthquake ground motions are presented and the results discussed. Comparisons of the responses of the structures with concrete and steel coupling beams are made, demonstrating the advantages of using steel beams to couple reinforced concrete walls.Key words: composite construction, coupled wall, diagonally reinforced concrete coupling beam, "flexure critical" steel coupling beam, seismic design, "shear critical" steel coupling beam.

Seismic performance evaluation of coupled wall system with novel replaceable steel truss coupling beams

2018 ◽  
Vol 22 (6) ◽  
pp. 1284-1296 ◽  
Author(s):  
Yong Li ◽  
Ye Liu ◽  
Shaoping Meng
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Coupled Wall ◽  
Steel Truss ◽  
Seismic Loadings ◽  
Wall System

Coupled wall systems are often used in high-rise buildings in zone of high seismic risk to provide lateral resistance to earthquake loading. Once damaged, reinforced concrete coupling beams are costly and time-consuming to repair post-earthquake. To enhance the seismic resilience for coupled wall structures, a novel replaceable steel truss coupling beam is first introduced. The proposed replaceable steel truss coupling beam consists of chord members at the top and bottom, respectively, and two buckling-restrained energy dissipaters are employed in the diagonal direction. The energy dissipaters can yield first before the wall piers and dissipate large amounts of energy to protect the main structure under seismic loadings. In addition, the energy dissipaters can be easily installed and post-earthquake repaired through pin connection with the chord members. This article mainly focused on the numerical and theoretical analyses of the proposed replaceable steel truss coupling beam, and nonlinear analytical models were developed in PERFORM-3D. An 11-story prototype structure was designed per Chinese code. The seismic response of hybrid coupled wall system with replaceable steel truss coupling beams was evaluated using nonlinear time history analysis and compared with the response of reinforced concrete coupled wall system with reinforced concrete coupling beams under seismic loadings. Results show that the proposed replaceable steel truss coupling beam leads to a good seismic response with reduced interstory drifts of the systems and rotational demand in the beams and wall piers due to a large energy dissipation capacity and overstrength.

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