An experimental study on cyclic behaviour of reinforced concrete connections

2007 ◽  
Vol 34 (4) ◽  
pp. 565-575 ◽  
Author(s):  
Gerson Moacyr Sisniegas Alva ◽  
Ana Lúcia Homce de Cresce El Debs ◽  
Mounir Khalil El Debs
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Seismic Analysis ◽  
Reinforcement Rate ◽  
Shear Capacity ◽  
Transverse Reinforcement ◽  
Rc Beam ◽  
Concrete Compressive Strength ◽  
Cyclic Behaviour

Beam-column joints are considered critical regions within the structural system — especially under seismic loading — requiring careful design. Results from tests on four exterior reinforced concrete (RC) beam-column subassemblages are presented in this paper as part of an experimental investigation on the behaviour of RC beam-column connections under reversal cyclic loading. The influence of joint transverse reinforcement rate and concrete compressive strength on the RC beam-column connection behaviour was investigated. It is concluded that concrete compressive strength is the major factor that governs the joint shear capacity. The experimental results also indicated that joint transverse reinforcement affects the load-displacement response of such connections.Key words: cyclic loading, seismic analysis, reinforced concrete structures, beam-column connection.

scholarly journals Influence of Patching on the Shear Failure of Reinforced Concrete Beam without Stirrup

2021 ◽  
Vol 6 (7) ◽  
pp. 97
Author(s):  
Stefanus Adi Kristiawan ◽  
Halwan Alfisa Saifullah ◽  
Agus Supriyadi
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Numerical Study ◽  
Unsaturated Polyester ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Rc Beam ◽  
Shear Span ◽  
Shear Cracking

Deteriorated concrete cover, e.g., spalling or delamination, especially when it occurs at the web of a reinforced concrete (RC) beam within the shear span, can reduce the shear capacity of the beam. Patching of this deteriorated area may be the best option to recover the shear capacity of the beam affected. For this purpose, unsaturated polyester resin mortar (UPR mortar) has been formulated. This research aims to investigate the efficacy of UPR mortar in limiting the shear cracking and so restoring the shear capacity of the deteriorated RC beam. The investigation is carried out by an experimental and numerical study. Two types of beams with a size of 150 × 250 × 1000 mm were prepared. The first type of beams was assigned as a normal beam. The other was a beam with a cut off in the non-stirrup shear span, which was eventually patched with UPR mortar. Two reinforcement ratios were assigned for each type of beams. The results show that UPR mortar is effective to hamper the propagation of diagonal cracks leading to increase the shear failure load by 15–20% compared to the reference (normal) beam. The increase of shear strength with the use of UPR mortar is consistently confirmed at various reinforcement ratios.

Guidelines for flexural design of FRP reinforced concrete beams

2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Large Diameter ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Concrete Compressive Strength ◽  
Load Carrying ◽  
Multiple Variables

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.

Analysis and Prospect of Size Effect on Normal Section Bearing Capacity of Reinforced Concrete Column

2013 ◽  
Vol 351-352 ◽  
pp. 422-426
Author(s):  
Yong Ping Xie ◽  
Lei Jia ◽  
Gang Sun
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Theoretical Analysis ◽  
Size Effect ◽  
Bearing Capacity ◽  
Concrete Column ◽  
Concrete Compressive Strength ◽  
Reinforced Concrete Column ◽  
Normal Section

With the development of modern constructional technique, more attention on the size effect is paid by academics and engineers. The normal section bearing capacity of Reinforced Concrete Column is analyzed by eccentrically compressed theory firstly. The size effect on normal section bearing capacity of reinforced concrete column is obtained by theoretical analysis and experimental summary. The size effect formula of concrete compressive strength is proposed. Finally, a research thinking of size effect on bearing capacity is suggested.

Structural Behavior of RC Cylinders Confined with High Strength Transverse Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 1321-1324
Author(s):  
Sang A. Cha ◽  
Cho Hwa Moon ◽  
Sang Woo Kim ◽  
Kil Hee Kim ◽  
Jung Yoon Lee
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Yield Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Structural Behavior ◽  
Transverse Reinforcement ◽  
Strength Concrete ◽  
High Rise ◽  
Compressive Strength Of Concrete

The number of high-rise reinforced concrete (RC) buildings is steadily increasing since 1980’s. The use of high strength concrete is indispensible for high-rise RC construction to ensure sufficient strength of the structure. The effect of high strength concrete can be significantly improved by the use of high strength and large size reinforcing bars. The yield strength of transverse reinforcement is limited in the current design codes to prevent possible sudden concrete failure due to over reinforcement. This paper presents the effects of the yield strength of transverse reinforcement and compressive strength of concrete on the structural behavior of reinforced concrete cylinders. Two parameters were considered in this investigation: compressive strength of concrete and the yield strength of transverse reinforcement (472MPa, 880MPa, and 1,430 MPa). Analytical and experimental results indicated that the structural behavior of RC cylinders confined with high strength transverse reinforcement is strongly influenced by compressive strength of concrete.

scholarly journals Construction of N-M Interaction Diagram for Reinforced Concrete Columns Strengthened with Steel Jackets Using Plastic Stress Distribution Method

2017 ◽  
Vol 3 (10) ◽  
pp. 929
Author(s):  
Mohannad Husain Al-Sherrawi ◽  
Hamza M. Salman
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Stress Distribution ◽  
Concrete Columns ◽  
Concrete Compressive Strength ◽  
Distribution Method ◽  
Reinforced Concrete Columns ◽  
Interaction Diagram ◽  
Steel Angle ◽  
Plastic Stress

No attempts have been made in developing the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method. Therefore, this paper presents an analytical model to construct the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method after assuming the behavior of strengthened column to be like composite column and including the effects of confinement on concrete compressive strength. The proposed model was compared with experimental results. The comparisons showed that the model is conservative and it reveals the ultimate strength of the strengthened column. A parametric study has been also carried out to investigate the influence of various parameters on the N-M interaction diagram of the strengthened column. These parameters were: dimensions of steel angle, yield stress of the steel angles, concrete compressive strength and the size of the reinforcement bars used in RC columns. The results made clear the effects of these parameters on the N-M interaction diagram, and encouraged the use of the model in preliminary strengthening studies.

scholarly journals Research on compressive strength of hybrid fiber reinforced concrete based on orthogonal design

2021 ◽  
Vol 261 ◽  
pp. 02019
Author(s):  
Tu-Sheng He ◽  
Meng-Qian Xie ◽  
Yang Liu ◽  
San-Yin Zhao ◽  
Zai-Bo Li
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Prediction Model ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Concrete Compressive Strength ◽  
Hybrid Fiber

The influence of steel fiber and polypropylene fiber mixed on compressive strength of high performance concrete (HPC) was studied. The steel fiber content (0.5%, 1.0%, 1.5%, 2.0%) (volume fraction, the same below), polypropylene fiber content (0.05%, 0.1%, 0.15%, 0.2%) and length (5mm, 6.5mm, 12mm, 18mm) were studied by L16 (45) orthogonal test for 28d ages, the range analysis and variance analysis of the test results are carried out, and the prediction model of compressive strength of hybrid fiber reinforced concrete was established. The results show that: The significant influence factor of concrete compressive strength is the volume fraction of polypropylene fiber, while the length of polypropylene fiber and the volume fraction of steel fiber are not significant; the concrete compressive strength with polypropylene fiber shows negative hybrid effect; The prediction model of compressive strength of hybrid fiber reinforced concrete has high accuracy, and the average relative errors is 2.96%.

Influence of Minimum Tension Steel Reinforcement on the Behavior of Singly Reinforced Concrete Beams in Flexure

2020 ◽  
Vol 38 (7A) ◽  
pp. 1034-1046
Author(s):  
Ali ِA. Abdulsada ◽  
Raid I. Khalel ◽  
Kaiss F. Sarsam
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Rectangular Cross Section ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Concrete Compressive Strength ◽  
Minimum Reinforcement ◽  
Flexural Reinforcement ◽  
New Formula

The requirements of minimum flexural reinforcement in the last decades have been a reason for controversy. The structural behavior of beams in bending is the best way of investigating and evaluating the minimum reinforcement in flexure. For this purpose, twelve singly reinforced concrete beams with a rectangular cross-section of (125 mm) width by (250 mm) height and (1800 mm) length were cast and tested under two-point loads up to failure. These beams were divided into three groups with different compressive strengths (25, 50, and 80 MPa). Each group consists of four beams with different amounts of tension steel reinforcement approximately equal to (0% Asmin, 50% Asmin, 100% Asmin and 150% Asmin), two bar diameters (Ø6 mm and Ø8 mm) were used as the longitudinal tension reinforcement with different yield and ultimate strengths, the minimum amount of reinforcement required is calculated based on ACI 318M-2014 code. The results show that for the reinforced concrete beams, the flexural reinforcement in NSC beams increases the first cracking load and the increment increased with an increasing amount of reinforcement, while for HSC beams the increasing in first cracking load are very little when the quantity of reinforcement less than the minimum flexural reinforcement and increased with the increasing amount above the minimum flexural reinforcement. The equation of ACI 318M-14 code gives adequate minimum flexural reinforcement for NSC and overestimate value for HSC up to (83 MPa), A new formula is proposed for HSC rectangular beams up to (90 MPa) concrete compressive strength by reducing the equation of ACI 318M-14 code for minimum flexural reinforcement by a factor depending on concrete compressive strength.  

Anchorage Capacity of Headed Bars in Steel Fiber Reinforced Concrete

2021 ◽  
Author(s):  
Payal Sachdeva ◽  
A.B. Danie Roy ◽  
Naveen Kwatra
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Concrete Compressive Strength ◽  
Pull Out

Headed bars (HB) with different head shapes (Square, Circular, and Rectangular) and bar diameters (db: 16, 20, and 25 mm) embedded in steel fiber reinforced concrete have been subjected to pull-out test. The influence of head shapes, concrete compressive strength (M20 and M40), db, and steel fibers (0, 0.5, 1, and 1.5%) on the anchorage capacity of HB have been evaluated. Numerical model for improving the anchorage capacity of HB has also been proposed. Results have revealed that the anchorage capacity of HB increases with the increase in concrete compressive strength, db, and steel fibers, which have been validated by non-linear regression analysis using dummy variables. Two failure modes namely, steel and concrete-blowout have been observed and the prevailing mode of failure is steel failure. Based on load-deflection curves and derived descriptive equations, it is observed that the circular HB has displayed the highest peak load.

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