scholarly journals Experimental Study on Reinforced Concrete Column Incased in Prefabricated Permanent Thin-Walled Steel Form

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Jae Yuel Oh ◽  
Deuck Hang Lee ◽  
Jungmin Lee ◽  
Kang Su Kim ◽  
Sung-Bae Kim
Keyword(s):  
Reinforced Concrete ◽  
Local Buckling ◽  
Initial Imperfection ◽  
Thin Plates ◽  
Compression Tests ◽  
Reinforced Concrete Column ◽  
Conventional Concrete ◽  
Rc Structures ◽  
Accidental Eccentricity ◽  
Thin Walled

Conventional construction methods of reinforced concrete (RC) structures generally require a long construction period and high costs due to many on-site temporary form works. In this study, a prefabricated permanent thin-walled steel form integrated with reinforcement cage (PPSFRC) was developed, and it makes for a fast-built construction by reducing the temporary form works. Axial compression tests were conducted on a total of 9 test specimens to investigate the structural performances of the newly developed columns. The proposed column construction method utilized relatively thinner steel plates compared to conventional concrete-filled tube (CFT) columns, but it was designed to have sufficient resistance performances against the lateral pressure of fresh concrete and to prevent the buckling of the thin plates by utilizing the steel angles and channel stiffeners prefabricated in the permanent thin-walled steel form. The experimental results showed that the column specimens fabricated by the PPSFRC method had better local buckling resistance and behaved in a more ductile manner compared to the conventional CFT columns. In addition, the axial strengths of the test specimens were compared with those estimated by design provisions, and the flexural moments induced by initial imperfection or accidental eccentricity of axial loads were also discussed in detail.

scholarly journals Behaviour of Hybrid Steel and FRP-Reinforced Concrete—ECC Composite Columns under Reversed Cyclic Loading

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4231 ◽  
Author(s):  
Fang Yuan ◽  
Liping Chen ◽  
Mengcheng Chen ◽  
Kaicheng Xu
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Plastic Hinge ◽  
Local Buckling ◽  
Hinge Region ◽  
Reinforced Concrete Column ◽  
Reversed Cyclic Loading ◽  
Reversed Cyclic ◽  
Frp Bars ◽  
Strength And Ductility

Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear–elastic property of FRP reinforcement. Hybrid steel—FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel—FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel—FRP-reinforced concrete—engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel—FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially.

scholarly journals Theoretical Local Buckling Behavior of Thin-Walled UHPC Flanges Subjected to Pure Compressions

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2130
Author(s):  
Jeonghwa Lee ◽  
Seungjun Kim ◽  
Keesei Lee ◽  
Young Jong Kang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Plastic Material ◽  
Local Buckling ◽  
Material Model ◽  
Failure Criteria ◽  
Structural Performance ◽  
Conventional Concrete ◽  
Buckling Behavior ◽  
Thin Walled

To enhance structural performance of concrete and reduce its self-weight, ultra-high-performance concrete (UHPC) with superior structural performance has been developed. As UHPC members with 180 MPa or above of the compressive strength can be designed, a rational assessment of thin-walled UHPC structural member may be required to prevent unexpected buckling failure that has not been considered while designing conventional concrete members. In this study, theoretical local buckling behavior of the thin-walled UHPC flanges was investigated using geometrical and material nonlinear analysis with imperfections (GMNIA). For the failure criteria of UHPC, a concrete damaged plasticity (CDP) model was applied to the analysis. Additionally, an elastic-perfectly plastic material model for steel materials was considered as a reference to establish differences in local buckling behavior between the UHPC and steel flanges. Finite element approaches were compared and verified based on test data in the literature. Finally, this study offers several important findings on theoretical local buckling and local bending behavior of UHPC flanges. The inelastic local buckling behavior of UHPC flanges was mainly affected by crack propagation due to its low tensile strength. Based on this study, possibility of the local buckling of UHPC flanges was discussed.

scholarly journals Finite element modeling of concrete confined with circular thin-walled steel sheet

2020 ◽  
Vol 156 ◽  
pp. 05009
Author(s):  
Ashando Hario Yudhanto ◽  
Bambang Piscesa ◽  
Mario M. Attard ◽  
Budi Suswanto ◽  
Priyo Suprobo
Keyword(s):  
Reinforced Concrete ◽  
Steel Sheet ◽  
Steel Tube ◽  
Point Of View ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Interface Behavior ◽  
Concrete Core ◽  
Earthquake Load ◽  
Thin Walled

For a reinforced concrete column to behave in a ductile manner without much loss on strength requires sufficient confinement to the concrete core. One way to provide confinement to the concrete core is to use external confining devices such as a series of thin-walled circular steel sheet tube to confine the concrete. This type of external confining device falls off on the categories of Steel Tube Confined Concrete (STCC). With the presence of a gap between the steel sheet, the buckling on the tube due to high axial stresses can be avoided. On the other hand, STCC also offers great advantages to strengthen a non-code conforming reinforced concrete column to achieve better resistance to withstand earthquake load. From the numerical analysis point of view, the important task to successfully model the STCC specimen lies in the modeling of the interface behavior between concrete and steel tube. For that purpose, in this paper, the 3D-NLFEA package is used to study the response of STCC. The analysis result is further compared with the available test results in the literature. From the analysis, the predicted response is excellent. Detailed discussion on the parameter of the interface behavior between concrete and steel tube is presented.

Bending Strength of Steel Fibre Reinforced Concrete Ribbed Slab Panel

2018 ◽  
Vol 15 (1) ◽  
pp. 15
Author(s):  
AMIR SYAFIQ SAMSUDIN ◽  
MOHD HISBANY MOHD HASHIM ◽  
SITI HAWA HAMZAH ◽  
AFIDAH ABU BAKAR
Keyword(s):  
Reinforced Concrete ◽  
Bending Strength ◽  
Steel Fibre ◽  
Concrete Slab ◽  
Future Application ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Conventional Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Bending Load

Nowadays, demands in the application of fibre in concrete increase gradually as an engineering material. Rapid cost increment of material causes the increase in demand of new technology that provides safe, efficient and economical design for the present and future application. The introduction of ribbed slab reduces concrete materials and thus the cost, but the strength of the structure also reduces due to the reducing of material. Steel fibre reinforced concrete (SFRC) has the ability to maintain a part of its tensile strength prior to crack in order to resist more loading compared to conventional concrete. Meanwhile, the ribbed slab can help in material reduction. This research investigated on the bending strength of 2-ribbed and 3-ribbed concrete slab with steel fibre reinforcement under static loading with a span of 1500 mm and 1000 mm x 75 mm in cross section. An amount of 40 kg/m steel fibre of all total concrete volume was used as reinforcement instead of conventional bars with concrete grade 30 N/mm2. The slab was tested under three-point bending. Load versus deflection curve was plotted to illustrate the result and to compare the deflection between control and ribbed slab. This research shows that SFRC Ribbed Slab capable to withstand the same amount of load as normal slab structure, although the concrete volume reduces up to 20%.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

Quasi-static Compressive Properties and Behavior of Single-cell Miura Origami Column Fabricated by 3D Printed PLA Material

2020 ◽  
Vol 3 (2) ◽  
pp. 66-73
Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari
Keyword(s):  
Single Cell ◽  
Peak Stress ◽  
Absorption Capacity ◽  
Compression Tests ◽  
Compressive Properties ◽  
Folding Pattern ◽  
Column Structure ◽  
Thin Walled ◽  
And Behavior ◽  
Initial Peak

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.

scholarly journals Degradation Monitoring in Reinforced Concrete with 3D Localization of Rebar Corrosion and Related Concrete Cracking

2021 ◽  
Vol 11 (15) ◽  
pp. 6772
Author(s):  
Charlotte Van Steen ◽  
Els Verstrynge
Keyword(s):  
Reinforced Concrete ◽  
Degradation Mechanism ◽  
Heterogeneous Material ◽  
Corrosion Damage ◽  
Corrosion Process ◽  
Internal Damage ◽  
Rc Structures ◽  
Degradation Monitoring ◽  
Rebar Corrosion ◽  
Width Measurements

Corrosion of the reinforcement is a major degradation mechanism affecting durability and safety of reinforced concrete (RC) structures. As the corrosion process starts internally, it can take years before visual damage can be noticed on the surface, resulting in an overall degraded condition and leading to large financial costs for maintenance and repair. The acoustic emission (AE) technique enables the continuous monitoring of the progress of internal cracking in a non-invasive way. However, as RC is a heterogeneous material, reliable damage detection and localization remains challenging. This paper presents extensive experimental research aiming at localizing internal damage in RC during the corrosion process. Results of corrosion damage monitoring with AE are presented and validated on three sample scales: small mortar samples (scale 1), RC prisms (scale 2), and RC beams (scale 3). For each scale, the corrosion process was accelerated by imposing a direct current. It is found that the AE technique can detect damage earlier than visual inspection. However, dedicated filtering is necessary to reliably localize AE events. Therefore, AE signals were filtered by a newly developed post-processing protocol which significantly improves the localization results. On the smallest scale, results were confirmed with 3D micro-CT imaging, whereas on scales 2 and 3, results were compared with surface crack width measurements and resulting rebar corrosion levels.

scholarly journals A Practical Finite Element Modeling Strategy to Capture Cracking and Crushing Behavior of Reinforced Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 506 ◽  
Author(s):  
Alexandre Mathern ◽  
Jincheng Yang
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Constitutive Relations ◽  
Fe Analysis ◽  
Rc Beams ◽  
Cracking Behavior ◽  
Concrete Cracking ◽  
Rc Structures ◽  
Nonlinear Fe Analysis ◽  
Modeling Strategy

Nonlinear finite element (FE) analysis of reinforced concrete (RC) structures is characterized by numerous modeling options and input parameters. To accurately model the nonlinear RC behavior involving concrete cracking in tension and crushing in compression, practitioners make different choices regarding the critical modeling issues, e.g., defining the concrete constitutive relations, assigning the bond between the concrete and the steel reinforcement, and solving problems related to convergence difficulties and mesh sensitivities. Thus, it is imperative to review the common modeling choices critically and develop a robust modeling strategy with consistency, reliability, and comparability. This paper proposes a modeling strategy and practical recommendations for the nonlinear FE analysis of RC structures based on parametric studies of critical modeling choices. The proposed modeling strategy aims at providing reliable predictions of flexural responses of RC members with a focus on concrete cracking behavior and crushing failure, which serve as the foundation for more complex modeling cases, e.g., RC beams bonded with fiber reinforced polymer (FRP) laminates. Additionally, herein, the implementation procedure for the proposed modeling strategy is comprehensively described with a focus on the critical modeling issues for RC structures. The proposed strategy is demonstrated through FE analyses of RC beams tested in four-point bending—one RC beam as reference and one beam externally bonded with a carbon-FRP (CFRP) laminate in its soffit. The simulated results agree well with experimental measurements regarding load-deformation relationship, cracking, flexural failure due to concrete crushing, and CFRP debonding initiated by intermediate cracks. The modeling strategy and recommendations presented herein are applicable to the nonlinear FE analysis of RC structures in general.

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