Moment redistribution in RC beams – A study of the influence of longitudinal and transverse reinforcement ratios and concrete strength

2014 ◽  
Vol 80 ◽  
pp. 11-23 ◽  
Author(s):  
Niklas Bagge ◽  
Alan O’Connor ◽  
Lennart Elfgren ◽  
Claus Pedersen
Keyword(s):  
Concrete Strength ◽  
Transverse Reinforcement ◽  
Rc Beams ◽  
Moment Redistribution

Flexural ductility of reinforced concrete beams with lap-spliced bars

2014 ◽  
Vol 41 (7) ◽  
pp. 594-604 ◽  
Author(s):  
Mehrollah Rakhshanimehr ◽  
M. Reza Esfahani ◽  
M. Reza Kianoush ◽  
B. Ali Mohammadzadeh ◽  
S. Roohollah Mousavi
Keyword(s):  
Reinforced Concrete ◽  
Bond Strength ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Transverse Reinforcement ◽  
Rc Beams ◽  
Flexural Ductility ◽  
Ductility Ratio ◽  
Strength And Ductility

In this paper, the flexural ductility of lap-spliced reinforced concrete (RC) beams is experimentally investigated. Twenty-four specimens were designed and manufactured for laboratory experiments. Concrete compressive strength, amount of transverse reinforcement over the splice length, and the diameter of longitudinal bars were selected as the main variables. The ductility of tested specimens is evaluated based on a previously defined ductility ratio. Results show that concrete strength and amount of transverse reinforcement over the splice have major effects on ductility. With an appropriate amount of transverse reinforcement, a satisfactory ductility response for different concrete strengths can be obtained. The CSA-A23.3-04 Standard provisions on bond strength and ductility of lap-spliced RC beams are evaluated and discussed. This study shows that the provisions in predicting the bond strength of lap-spliced concrete beams are adequate but may not achieve a satisfactory performance for ductility. An equation is proposed to achieve the appropriate ductility.

scholarly journals Effect of Uncertainties in Material and Structural Detailing on the Seismic Vulnerability of RC Frames Considering Construction Quality Defects

2020 ◽  
Vol 10 (24) ◽  
pp. 8832
Author(s):  
Siyun Kim ◽  
Taehwan Moon ◽  
Sung Jig Kim
Keyword(s):  
Material Properties ◽  
Seismic Vulnerability ◽  
Concrete Strength ◽  
Transverse Reinforcement ◽  
Construction Quality ◽  
Uncertain Variables ◽  
Rc Frames ◽  
Structural Detailing ◽  
Global And Local ◽  
The Impact

This paper evaluates the effect of construction quality defects on the seismic vulnerability of reinforced concrete (RC) frames. The variability in the construction quality of material properties and structural detailing is considered to assess the effect on the seismic behavior of RC frames. Concrete strength and yield strength of the reinforcement are selected as uncertain variables for the material properties, while the variabilities in the longitudinal reinforcement ratio and the volumetric ratio of transverse reinforcement are employed for structural detailing. Taking into account the selected construction quality uncertainties, the sensitivity analysis of the seismic vulnerability of the RC frames is performed and the impact of significant parameters is assessed at the global and local levels. This extensive analytical study reveals that the seismic vulnerability of the selected RC frame is particularly sensitive to concrete strength and the volumetric ratio of transverse reinforcement.

scholarly journals Experimental Study of Composite Hollow RC Column under Uniaxial Compressive Load

2019 ◽  
Vol 9 (3) ◽  
pp. 373
Author(s):  
Deokhee Won ◽  
Seungjun Kim ◽  
Jihye Seo ◽  
and Young-Jong Kang
Keyword(s):  
Experimental Study ◽  
Concrete Strength ◽  
Compressive Load ◽  
High Strength ◽  
Transverse Reinforcement ◽  
Strength Concrete ◽  
Rc Column ◽  
Steel Composite ◽  
Normal Strength ◽  
Concentric Loading

This paper presents an experimental study of the behavior of a steel-composite hollow reinforced concrete (RC) column under concentric loading. The effects of important variables, such as concrete strength, inner tube thickness, hollow ratio, column diameter, and transverse reinforcement space, are presented in this study. The failure of composite hollow RC columns is characterized by the formation of an inclined shear sliding plane. When the column had a highly confined effect, the inclination of the shear sliding plane was 45°. This study shows that the required performance is achieved when the splice providing transverse reinforcement is fully bonded. Furthermore, the inner tube experiences buckling failure after reaching its maximum strength. The steel-composite hollow RC column with high-strength concrete (HSC) has lower ductility and toughness compared to a column with normal-strength concrete (NSC).

scholarly journals Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces

2016 ◽  
Vol 23 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Robert KOWALSKI ◽  
Michał GŁOWACKI ◽  
Marian ABRAMOWICZ
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Bending Moment ◽  
Middle Part ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Bending Moments ◽  
Rc Beams ◽  
Shear Forces ◽  
Load Bearing Capacity

When multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending moments occurs and the values of sagging moment in span cross-sections decrease while the values of hogging moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their cross-section. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam span where there was no transverse reinforcement.

Finite Element Analysis of Shear Strength of Reinforced Concrete Beams after Fire

2013 ◽  
Vol 671-674 ◽  
pp. 474-478 ◽  
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Bi Zhao
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Exposure Time ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Fire Exposure ◽  
Shear Span ◽  
Strength And Stiffness

Shear strength and stiffness of fire-damaged reinforced concrete (RC) beams were researched. The nonlinear finite element method (FEM) was developed to simulate shear strength of fire-damaged RC beams. Considering mechanical properties deterioration of concrete and steel reinforcing bar, the parameters of fire-damaged RC beams, including fire exposure time, shear span to depth ratios, concrete strength, diameters of stirrups and spacing of stirrups, were analyzed. Based on numerical analysis, the change of shear strength and stiffness of fire-damaged RC beams were identified. The results showed that shear strength and stiffness of fire-damaged RC beams changed under different parameters. With increase of fire exposure time or increase of shear span to depth ratio or decrease of concrete strength, shear strength and stiffness of fire-damaged RC beams descended obviously. With decrease of diameters of stirrups or increase of spacing of stirrups, shear strength of fire-damaged RC beams descended gradually, but stiffness of fire-damaged RC beams had little change.

scholarly journals Axial Compressive Behaviour of Square Through-Beam Joints between CFST Columns and RC Beams with Multi-Layers of Steel Meshes

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2482
Author(s):  
Weining Duan ◽  
Jian Cai ◽  
Xu-Lin Tang ◽  
Qing-Jun Chen ◽  
Chun Yang ◽  
...  
Keyword(s):  
Axial Compression ◽  
Mechanical Performance ◽  
Concrete Strength ◽  
Volume Ratio ◽  
Design Criterion ◽  
Design Methods ◽  
Rc Beams ◽  
Compressive Behaviour ◽  
Joint Area ◽  
Cfst Columns

The axial compressive behaviour of an innovative type of square concrete filled steel tube (CFST) column to reinforced concrete (RC) beam joint was experimentally investigated in this paper. The innovative joint was designed such that (i) the steel tubes of the CFST columns were completely interrupted in the joint region, (ii) the longitudinal reinforcements from the RC beams could easily pass through the joint area and (iii) a reinforcement cage, including a series of reinforcement meshes and radial stirrups, was arranged in the joint area to strengthen the mechanical performance of the joint. A two-stage experimental study was conducted to investigate the behaviour of the innovative joint under axial compression loads, where the first stage of the tests included three full-scale innovative joint specimens subjected to axial compression to assess the feasibility of the joint detailing and propose measures to further improve its axial compressive behaviour, and the second stage of the tests involved 14 innovative joint specimens with the improved detailing to study the effect of the geometric size of the joint, concrete strength and volume ratio of the steel meshes on the bearing strengths of the joints. It was generally found from the experiments that (i) the innovative joint is capable of achieving the design criterion of the ‘strong joint-weak member’ with appropriate designs, and (ii) by decreasing the height factor and increasing the volume ratio of the steel meshes, the axial compressive strengths of the joints significantly increased, while the increase of the length factor is advantageous but limited to the resistances of the joint specimens. Because of the lack of existing design methods for the innovative joints, new design expressions were proposed to calculate the axial compression resistances of the innovative joints subjected to bearing loads, with the local compression effect, the confinement effect provided by the multi-layers of steel meshes and the height effect of concrete considered. It was found that the proposed design methods were capable of providing accurate and safe resistance predictions for the innovative joints.

Experimental Study on Post-Anchoring Pulling-Out Bearing Capacity of Inorganic Materials in Concrete Test Cubes

2012 ◽  
Vol 166-169 ◽  
pp. 420-425
Author(s):  
Shi Qi Cui ◽  
Li Ping Jiang ◽  
Bo Cheng ◽  
Tao Wang
Keyword(s):  
Experimental Study ◽  
Theoretical Basis ◽  
Inorganic Material ◽  
Concrete Strength ◽  
Technical Specification ◽  
Concrete Cover ◽  
Adhesive Property ◽  
Inorganic Materials ◽  
Transverse Reinforcement ◽  
Cover Thickness

Through the test and observe the failure deformation in concrete test cube, the paper analyze the influence of concrete strength, concrete cover thickness, internal reinforcement cage(transverse reinforcement), reinforcement diameter on the inorganic material reinforcement adhesive property, providing theoretical basis for the code of Technical specification for post-anchoring used in concrete structure with inorganic anchoring material.

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