Strength and deflection prediction of double-curvature reinforced concrete squat walls

Peak shear strength is a critical parameter in the evaluation of the seismic performance of structural walls. Different equations have been proposed to predict the peak shear strength of reinforced concrete squat walls in literature, which assume lateral loading is parallel to the web. In reality, however, seismic waves can reach structures from any direction, which necessitates the studies on the behavior of structural walls under various lateral loading directions. Unlike rectangular walls, non-rectangular walls naturally possess the capacity to resist lateral loads in both transverse and longitudinal directions. To explore the peak shear strength of such walls under different lateral loading directions, a widely used nonlinear finite element software Diana 9.4 was utilized in this article. Appropriate modeling approaches were first selected and further validated by simulating relevant experiments. Then a comprehensive parametric study was carried out to investigate the influence of lateral loading directions and other important parameters.

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Effect of steel-fiber reinforced concrete on the fire resistance of concrete-filled steel tubular columns under simultaneous axial loading and double curvature bending

Proceedings of the 11th International Conference on Structures in Fire (SiF2020) ◽

10.14264/4767f7d ◽

2020 ◽

Author(s):

Takuya Kinoshita ◽

Yusuke Shintani ◽

Tomohito Okazaki ◽

Toshihiko Nishimura ◽

J. Y. Richard Liew

Keyword(s):

Reinforced Concrete ◽

Fire Resistance ◽

Steel Fiber ◽

Axial Loading ◽

Fiber Reinforced Concrete ◽

Fiber Reinforced ◽

Steel Fiber Reinforced Concrete ◽

Tubular Columns ◽

Double Curvature

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

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2017.187 ◽

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.

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