scholarly journals Experimental Study on Bond Behavior between Plain Reinforcing Bars and Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guohua Xing ◽  
Cheng Zhou ◽  
Tao Wu ◽  
Boquan Liu
Keyword(s):  
Aluminium Alloy ◽  
Structural Characteristics ◽  
Bond Stress ◽  
Reinforcing Bars ◽  
Bond Slip ◽  
Bond Behavior ◽  
Reinforcing Bar ◽  
Test Parameters ◽  
Steel Bars ◽  
Plain Bars

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.

Experimental Study on Bond Behavior of GFRP-to-Cement Mortar

2011 ◽  
Vol 94-96 ◽  
pp. 543-546
Author(s):  
Ning Zhang ◽  
Ai Zhong Lu ◽  
Yun Qian Xu ◽  
Pan Cui
Keyword(s):  
Aluminium Alloy ◽  
Cement Mortar ◽  
Bond Stress ◽  
Reinforcing Bars ◽  
Bond Performance ◽  
Gfrp Bars ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Average Bond

Direct pull-out tests were performed to evaluate the bond performance of glass fiber-reinforced polymer (GFRP) reinforcing bars in cement mortar. Specimens with different bar diameters and different grouted lengths (i.e., 5d, 10d and 15d, d is the diameter of bars) are prepared for the pull-out tests. For comparison, specimens with plain aluminium alloy bars (AAB) were tested as well. The result shows that the average bond stress between plain aluminium alloy bars and cement is much smaller than that between the deformed GFRP bars and cement; thin GFRP bars tended to have larger average bond stress; the shorter the grouted length, the smaller the maximum average bond stress. Only part of grouted length undertakes the bond stress and the length depends on the shear modulus of GFRP and the surrounding material.

Study on Evaluation Method of Corroded Reinforcing Steel

2010 ◽  
Vol 26-28 ◽  
pp. 1184-1189 ◽  
Author(s):  
Ying Zi Zhang ◽  
Ying Fang Fan ◽  
Hong Nan Li ◽  
Xue Nan Wu
Keyword(s):  
Weight Loss ◽  
Energy Loss ◽  
Cross Section ◽  
Strain Energy ◽  
Evaluation Method ◽  
Reinforcing Bars ◽  
Reinforcing Bar ◽  
Important Index ◽  
Steel Bars ◽  
Strain Energy Loss

Corrosion ratio is an important index to study the mechanical deteriorates of the steel bars, which has a significant effect to evaluate the residual bearing capacity of reinforced concrete structures. To investigate the mechanical properties of the corroded steel bars, Strain energy loss as corrosion ratio is firstly proposed. Tensile test are conducted on ribbed and plain steels, which are corroded by acceleration corrosion method. Comparing with the weight loss and cross-section loss to describe the effect of corrosion of reinforcing bar, the strain energy loss of reinforcing bars is calculated by Simpson quadrature. Results from this paper and other researchers’ test suggest that the strain energy loss may be a better parameter than weight loss or section loss which to assess the corroded steel bars.

Numerical Simulation of Bond Properties of Steel Bars in Concrete with Machine-Made Sand

2012 ◽  
Vol 238 ◽  
pp. 176-180
Author(s):  
Shun Bo Zhao ◽  
Xin Xin Ding ◽  
Shi Ming Liu
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Theoretical Method ◽  
Finite Element Models ◽  
Bond Properties ◽  
Ansys Software ◽  
Bond Slip ◽  
Bond Behavior ◽  
Steel Bar ◽  
Steel Bars

Based on the experimental studies, finite element models were built using ANSYS software to simulate the bond properties of steel bars in machine-made-sand concrete (MSC), which considered the nonlinear bond behavior of interface between steel bar and MSC. The concrete strength and the bond length of steel bar are considered as the main parameters for calculation. The complete bond-slip curves of plain and deformed steel bars are well simulated comparing those obtained from the experimental studies. The study gives an theoretical method to analyze the bond properties of steel bar in MSC.

Experimental Study on Measuring the Steel Stress via FBG Sensors

2014 ◽  
Vol 548-549 ◽  
pp. 663-667 ◽  
Author(s):  
Hong Wei Lin ◽  
Yu Xi Zhao
Keyword(s):  
Experimental Study ◽  
Bond Stress ◽  
Strain Gauges ◽  
Bond Behavior ◽  
Fbg Sensor ◽  
Pullout Tests ◽  
Steel Bar ◽  
Steel Bars ◽  
Fbg Sensors

Studying the bond stress-slip relationship between concrete and corroded steel bar by cutting the steel bars into two separate parts and attaching electric strain gauges in the slots is no longer suitable. To overcome the disadvantages of electric strain gauges in the measuring the stress of corroded steel bars, this paper introduced a new kind of FBG sensor measuring steel stress. By calibration tests, the proportion coefficient between variation of wavelength and steel strain was confirmed as 0.0012. The bond behavior between concrete and steel bar was also investigated by performing pullout tests on beam end specimens.

Bond-Slip Constitutive Behavior between Fiber-Reinforced Polymer and Masonry

2012 ◽  
Vol 446-449 ◽  
pp. 3165-3170 ◽  
Author(s):  
Yi Zheng ◽  
Jin Qing Jia ◽  
Li Li ◽  
Shi Kuan You
Keyword(s):  
Constitutive Models ◽  
Bond Stress ◽  
Fiber Reinforced Polymer ◽  
Strain Gauges ◽  
Test Results ◽  
Hydraulic Jack ◽  
Bond Slip ◽  
Bond Behavior ◽  
Frp Composite ◽  
Reinforced Polymer

To study the bond behavior and the force transference of FRP plates adhered to masonry. In this paper, experiments of anchorage strength of FRP attached to masonry are done, a 100KN capacity hydraulic jack activated by a manual pump was used to load the specimen. The tensile strength was measured by using a loading transducer, and strain gauges were mounted directly onto the surface of the FRP composite to measure the strain during application of load. Besides the strain and bond stress development and distribution under every grade of loading were studied. Test results show that the maximum local bond stress is not influenced by the FRP bond length, instead it increases with masonry strength. At the same time, the local bond stress--slip curve is obtained. Based on the test results, two new bond stress-slip constitutive models between FRP and masonry were proposed and they turned out to be good matches to the experimental results, which indicate its valuable references for the corresponding codes and engineering applications.

scholarly journals Numerical Evaluation of Bond Behavior of Ribbed Steel Bars or Seven-wire Strands Embedded in Lightweight Concrete

2020 ◽  
Author(s):  
Mohammed A. Abed ◽  
Zaher Alkurdi ◽  
Ahmad Kheshfeh ◽  
Tamás Kovács ◽  
Salem Nehme
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Lightweight Concrete ◽  
Reinforced Concrete Structures ◽  
Bond Slip ◽  
Bond Behavior ◽  
Pull Out ◽  
Steel Bars ◽  
Maximum Crack ◽  
3D Software

The bond-slip relationship between concrete and steel is significant in evaluating the nonlinear behavior of reinforced concrete structures. The force transmitted by the bond in reinforced concrete structures was studied numerically in high-strength, lightweight concrete with ribbed reinforcing steel bar or seven-wire strand, using ATENA 3D software. The first part of the study was a validation of the model based on the actual results of standardized pull-out tests using the software. Subsequently, the bond behavior was studied, where a four-point static bending test was modeled based on the real bond-slip relationship of the pull-out test. It was deduced that the ATENA 3D software can simulate the experimental tests and provide meaningful results. In addition, inferred from the numerical modeling, the maximum crack width and the mid-span deflection of the reinforced concrete beam increased when the bond stress between the concrete and the reinforcing steel bars was decreased. When a high amount of reinforcement (two strands) was used, concrete failure occurred before the strands yielded. However, further increase of the bond stress also decreased the maximum crack width and mid-span deflection. The failure occurred due to the increase in the strand yielding point by using one strand as a reinforcement of the beam.

scholarly journals Pullout performance of steel bars partially bonded in concrete with epoxy resin

2018 ◽  
Vol 11 (3) ◽  
pp. 598-619
Author(s):  
R. H. SOUZA ◽  
M. E. TAVARES ◽  
D. V. FERNANDES
Keyword(s):  
Epoxy Resin ◽  
Cast Steel ◽  
Steel Reinforcement ◽  
Reinforcing Bars ◽  
Structural Bonding ◽  
Test Parameters ◽  
Steel Bars ◽  
Existing Structure ◽  
Bar Diameter ◽  
Sizeable Reduction

Abstract The installation of new reinforcing bars onto an existing structure is a common practice in civil construction both for old and new structures. The use of anchors has been extensively studied and normalized. The placement of steel reinforcement bars in holes filled with epoxy resin, despite their wide use, still lacks a satisfactory methodology for the design of such systems. In this context, the aim of this paper is to present the results of an experimental programme for confined pullout tests, comparing the performance of cast steel reinforcement bars to that of bars bonded to concrete with epoxy resin. The investigated test parameters included the bar diameter, the embedment length and the resin thickness. Tests results showed a significant efficiency of epoxy resin as structural bonding agent and allowed the verification of sizeable reduction in the anchorage lengths for bonded bars.

scholarly journals Modeling Uniaxial Bond Stress–Slip Behavior of Reinforcing Bars Embedded in Concrete with Different Strengths

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 783
Author(s):  
Chao-Wei Tang
Keyword(s):  
Compressive Strength ◽  
Bond Stress ◽  
Constitutive Relationship ◽  
Central Position ◽  
Test Results ◽  
Reinforcing Bars ◽  
Cross Sectional ◽  
Reinforcing Bar ◽  
Cross Sectional Dimension ◽  
Center Section

This paper aims to study the uniaxial bond stress–slip characteristics of reinforcing bars embedded in concrete with different strengths. Tests were conducted on tension–pull specimens that had a cross-sectional dimension with a reinforcing bar embedded in the center section. The experimental variable was the concrete compressive strength (20, 40, and 60 MPa). The test results show that in the specimen subjected to any fixed load, the maximum value of the concrete strain occurred around the central position, and its value increased as the compressive strength of the concrete increased. Depending on the embedded position of the steel bars, the bond stress–slip relationship was also different. In addition, the analytical results indicate that the proposed bond stress–slip constitutive relationship is very accurate in describing the true bond stress–slip relationship.

scholarly journals Bond Stress between Steel-Reinforced Bars and Fly Ash-Based Geopolymer Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yifei Cui ◽  
Peng Zhang ◽  
Jiuwen Bao
Keyword(s):  
Construction Materials ◽  
Bond Stress ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Reinforcing Bars ◽  
Bond Behaviour ◽  
Relative Slip ◽  
Pull Out ◽  
Steel Bars ◽  
Commercial Steel

Geopolymer concrete has been regarded as one of the most important green construction materials, which has been restrained in engineering applications partially due to a lack of bond studies. The structural performance of the reinforced concrete components primarily relies on the sufficient bond between the concrete and the reinforcing bars. Before being utilized in any concrete structure, GPC must demonstrate that it possesses understandable bond behaviour with commercial steel reinforcements. This work presents an experimental investigation on the bond stress of steel bars in reinforced geopolymer concrete (GPC) structures. Standard beam-end pull-out tests were conducted on GPC specimens reinforced with 16 mm plain and ribbed bars that were equipped with electrical resistance strain gauges. The longitudinal variation in the bond stress in the GPC beams during the pull-out tests was calculated and plotted, as well as the stress in steel bars. The cracks on the bond area of the GPC were compared with those of the corresponding ordinary Portland cement concrete (OPC), as well as the steel stress and bond stress. The results showed that the relative slip between plain bar and geopolymer concrete varies from 30–450 microns from the loaded end to the free end when the bond stress decreased by 83%. The relative slip between ribbed bar and geopolymer concrete varies from 280–3,000 microns from the loaded end to the free end when the bond stress decreased by 57%. Generally, GPC is different from OPC in terms of bond stress distribution.

scholarly journals Study on the Bending and Joint Performances of Reinforced Concrete Beams Using High-Strength Rebars

2021 ◽  
Vol 13 (6) ◽  
pp. 3482
Author(s):  
Seoungho Cho ◽  
Myungkwan Lim ◽  
Changhee Lee
Keyword(s):  
Yield Strength ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
High Yield ◽  
Performance Tests ◽  
Reinforcing Bars ◽  
Joint Performance ◽  
Lap Splice ◽  
Reinforcing Bar ◽  
Nominal Strength

High-strength reinforcing bars have high yield strengths. It is possible to reduce the number of reinforcing bars placed in a building. Accordingly, as the amount of reinforcement decreases, the spacing of reinforcing bars increases, workability improves, and the construction period shortens. To evaluate the structural performance of high-strength reinforcing bars and the joint performance of high-strength threaded reinforcing bars, flexural performance tests were performed in this study on 12 beam members with the compressive strength of concrete, the yield strength of the tensile reinforcing bars, and the tensile reinforcing bar ratio as variables. The yield strengths of the tensile reinforcement and joint methods were used as variables, and joint performance tests were performed for six beam members. Based on this study, the foundation for using high-strength reinforcing bars with a design standard yield strength equal to 600 MPa was established. Accordingly, mechanical joints of high-strength threaded reinforcing bars (600 and 670 MPa) can be used. All six specimens were destroyed under more than the expected nominal strength. Lap splice caused brittle fractures because it was not reinforced in stirrup. Increases of 21% to 47% in the loads of specimens using a coupler and a lock nut were observed. Shape yield represents destruction—a section must ensure sufficient ductility after yielding. Therefore, a coupler and lock nut are effective.

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