scholarly journals THE BOND BEHAVIOR OF REINFORCING BARS THROUGH THE INTERIOR OF THE BEAM COLUMN JOINT

Author(s):  
SHIZUO HAYASHI ◽  
TOSHIYUKI MORIMOTO ◽  
SEIJI KOKUSHO
2021 ◽  
Author(s):  
Aamer Abbas ◽  
◽  
Yaqoob Yaqoob ◽  
Ola Hussein ◽  
Ibrahim Al-Ani ◽  
...  

This study presents experimentally the bond behavior of light-weight concrete specimens with grouted reinforcing bars in comparison with conventional concrete specimens. A total of (9) pull-out specimens were studied; (3) specimens of conventional concrete, (3) specimens of light-weight concrete, and other (3) specimens of grouted light-weight concrete. Two variables are adopted in this investigation: specimen width and type of concrete (conventional concrete, light-weight concrete and grouted light-weight concrete). The study contains a discussion of the general behavior of the specimens in addition to the study of the ultimate bond capacity, maximum bond stresses and the relationship between the stress and the slip for different pull-out specimens. Results show that bond strength is highest for the largest specimen size (bond strength of grouted light-weight concrete specimen with specimen width 400 mm is higher than that of the specimen with (200 mm) width by about (13.13%)). Also, bond strength is highest for the grouted light-weight concrete specimen (bond strength of grouted light-weight concrete specimen is higher than conventional concrete specimen by (11.11%)).


2000 ◽  
Vol 27 (3) ◽  
pp. 490-505 ◽  
Author(s):  
Mostafa Elmorsi ◽  
M Reza Kianoush ◽  
W K Tso

A new finite element model for reinforced concrete beam-column joints is proposed. The model considers the effects of bond-slip and shear deformations in the joint panel region. The problems associated with modeling bond-slip of anchored reinforcing bars are discussed. The proposed bond-slip model is examined at the element level by comparing its predictions with other analytical and experimental results. The ability of the model to simulate bond deterioration and eventual pullout of anchored reinforcing bars under severe cyclic excitation is demonstrated. This model is incorporated into the global beam-column joint element. Further comparisons are made between the predictions of the proposed beam-column joint model and other analytical and experimental results under reversed cyclic loading to show the validity of the model to describe the bond-slip behavior of the joints.Key words: bond, bond-slip, finite element, beam-column, reinforced concrete, cyclic.


2010 ◽  
Vol 7 (5) ◽  
pp. 403-419 ◽  
Author(s):  
Feng Shang ◽  
Xuhui An ◽  
Seji Kawai ◽  
Tetsuya Mishima

2013 ◽  
Vol 688 ◽  
pp. 222-229
Author(s):  
Özgür Yurdakul ◽  
Özgür Avşar ◽  
Kadir Kilinç

Earthquake is one of the most destructive natural disasters that cause loss of life and property in the earthquake prone regions. Unsuitable soil conditions, inadequate material properties and deficiencies in the structural system can lead to costly seismic damages to structures. In this study, damages caused by the earthquake were examined for reinforced concrete beam-column joints. The most common damage type observed in earthquakes is the beam-column joint damage that decreases the lateral load bearing capacity and might be the reason for total collapse of structures. Weak bonding between concrete and reinforcing bars, absence of transverse reinforcement and incapable shear strength of RC beam-column joint are the most common causes for RC beam-column joint damage. After numerous experimental works, different strengthening methods were developed in literature. This paper discusses various strengthening methods including conventional and new techniques as well as their technological application details and the issues arise in practice


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guohua Xing ◽  
Cheng Zhou ◽  
Tao Wu ◽  
Boquan Liu

To evaluate the bond behavior between the reinforcing bar and surrounding concrete, a total of six-group pullout specimens with plain steel bars and two-group specimens with deformed steel bars, serving as a reference, are experimentally investigated and presented in this study. The main test parameters of this investigation include embedment length, surface type of reinforcing bars, and bar diameter. In particular, the bond mechanism of plain steel reinforcing bars against the surrounding concrete was analyzed by comparing with six-group pullout specimens with aluminium alloy bars. The results indicated that the bond stress experienced by plain bars is quite lower than that of the deformed bars given equal structural characteristics and details. Averagely, plain bars appeared to develop only 18.3% of the bond stress of deformed bars. Differing from the bond strength of plain steel bars, which is based primarily on chemical adhesion and friction force, the bond stress of aluminium alloy bars is mainly experienced by chemical adhesion and about 0.21~0.56 MPa, which is just one-tenth of that of plain steel bars. Based on the test results, a bond-slip model at the interface between concrete and plain bars is put forward.


Author(s):  
Ju-Yun Hu ◽  
Won-Kee Hong ◽  
Seon-Chee Park ◽  
Jisoon Kim

The authors proposed steel beam-column connections for precast concrete frames in previous studies. The steel-concrete composite frames provided fast assembly time as steels with economy of concrete structures. However, when enough space is not available at column-beam joints steel sections from beams cannot be connected with column brackets. This paper suggests that some vertical reinforcing bars are disconnected at joints by connecting vertical steel reinforcements to steel plates placed above and below column steels to provide load transferring path. Loads from re-bars are transferred to steel plates, column steels and back to steel plates and re-bars below column steels. Re-bars connected to steel plates by bolts at above and below column steel are discontinued at joint to provide spaces for connections between column brackets and beam steels. Extensive experiments were performed to verify load transfer from re-bars to steel plates above joints and steel plates to re-bars below joint. The flexural load bearing capacity of a column with total of 24 vertical re-bars were compared to columns with discontinuous re-bars at joints. The number of discontinuous re-bars at joint used in column specimen was 0 (0.0%), 4 (16.7%), 12 (50.0%), and 20 (83.3%). The numbers in parenthesis are the percentages of discontinuous rebars to the total number of vertical re-bars of control column. Experiments showed how loads from vertical steel reinforcements that were cut off at joints were transferred to steel plate. The test results also demonstrated that a part of flexural capacities were reduced for specimen with discontinuous vertical re-bars. The reduction of 6.0 %, 13.7% and 54.0% of flexural capacities were observed for columns with 4 (16.7%), 12 (50.0%) and 20 (83.3%) discontinuous vertical rebars, respectively. The test results can be used to design vertical reinforcing bars and column joints that can provide space for column brackets to which steel members of beams are connected.


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