Experimental Study on Effects of Fatigue Loading History on Bond Behavior between Steel Bars and Concrete

2016 ◽  
Vol 711 ◽  
pp. 673-680 ◽  
Author(s):  
Zhiwen Ye ◽  
Wei Ping Zhang ◽  
You Hu ◽  
Xiang Lin Gu
Keyword(s):  
Experimental Study ◽  
Bond Strength ◽  
Fatigue Loading ◽  
Critical Value ◽  
Concrete Cover ◽  
Repeated Loading ◽  
Loading History ◽  
Bond Behavior ◽  
Pull Out ◽  
Steel Bars

This paper presents an experimental investigation on the influence of fatigue loading history on bond behavior between steel bars and concrete. Reinforced concrete specimens were subjected to fatigue loadings with different amplitudes and cycles before undergoing eccentric pull-out tests. Tests revealed that all specimens failed with the splitting of the concrete cover. With increased loading cycles, the concrete in front of transverse ribs usually becomes denser at the beginning. Meanwhile, the initial bond stiffness and the bond strength increased, while the slip corresponding to the peak bond stress decreases. With the further increase of loading cycles, the bond strength begins to decrease after it reaches a critical value. This study determined that for specimens subjected to repeated loading with a larger amplitude, fewer cycles are needed for the bond strength to go up to the critical bond strength.

Effects of Fatigue Damage on Bond Behavior between Corroded Rebar and Concrete

2019 ◽  
Author(s):  
Yunpeng Zhang ◽  
Weiping Zhang ◽  
You Hu
Keyword(s):  
Bond Strength ◽  
Fatigue Damage ◽  
Current Method ◽  
Fatigue Loading ◽  
Repeated Loading ◽  
Relative Slip ◽  
Pull Out ◽  
Bond Degradation ◽  
Impressed Current ◽  
Different Levels

Bond degradation due to rebar corrosion and fatigue loading may affect the serviceability and even safety of reinforced concrete (RC) bridges. 15 specimens confined with stirrups were cast for eccentric pull-out tests, and 12 of them were corroded with the target mass loss of 0.03 by the impressed current method. Monotonic pull-out tests were conducted on three corroded and three uncorroded specimens. Wavy descending branch was found in bond stress-slip test curves of uncorroded specimens attributed to stirrup confinement, however it disappeared in those curves of the corroded specimens due to the corrosion loss of rebar transverse ribs. Based on the tested monotonic bond strength, the other nine corroded specimens of different fatigue damages were obtained through repeated loading with different levels and cycles before undergoing monotonic pull-out tests. It is observed that the relative slip increases with a gradually decreasing rate as the loading cycles increase. The monotonic tests of specimens with fatigue damage show that the bond strength increases to a certain value and then decreases with the increase of fatigue loading cycles. Moreover, the higher the loading level is, the fewer cycles are needed to reach the maximum bond strength. In addition, the peak slip corresponding to bond strength decreases with the increase of fatigue loading cycles.

scholarly journals An Experimental Study on Effects of Corrosion and Stirrups Spacing on Bond Behavior of Reinforced Concrete

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1327
Author(s):  
Konstantinos Koulouris ◽  
Charis Apostolopoulos
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Bond Strength ◽  
Mass Loss ◽  
Corrosion Damage ◽  
Ongoing Research ◽  
Average Width ◽  
Concrete Cracking ◽  
Bond Behavior ◽  
Pull Out

The current experimental study consists of part of an extensive and ongoing research on bond behavior of RC elements damaged by corrosion, focusing on stirrups spacing effect on bonding. For this, RC specimens with different cases of stirrups spacing were casted. Accelerated corrosion was induced in order to simulate the slow process of nature corrosion on RC specimens and the corrosion damage was estimated in terms of mass loss of steel bars and average width of surface concrete cracking. Subsequently, pull-out tests were carried out to examine the bonding resistance between steel and concrete. The study indicates the great influence of density of stirrups on the percentage mass loss of the embedded reinforcing bar, accompanied by width of surface concrete cracking, as well as on bond strength between steel and concrete. The results of bond stress–slip curves show that the densification of stirrups plays a significant role in bonding, leading to higher bond strength values and delaying the degradation of bond loss as corrosion damage increases. However, it becomes apparent that, although the densification of stirrups (Φ8/60 mm) result in the full anchorage of steel-reinforcing bars, it may be inappropriate, since it can lead to a substantial increase in costs and a rapid rise in corrosion rate, due to potential increase. Furthermore, the recorded values of relative slip at bond strength are between 1 and 3 mm, regardless of corrosion damage or concrete cracking, which depends on the ribs geometry and crushing of concrete in front of them. To conclude, the results of the present manuscript indicate that the increase in transverse reinforcement (stirrups) percentage plays a key role in the durability of reinforced concrete elements and in bond strength maintenance between rebar and concrete.

Size Effect on the Bond Behavior of Grouted Reinforcing Bars Embedded in Light-weight Concrete

2021 ◽  
Author(s):  
Aamer Abbas ◽  
◽  
Yaqoob Yaqoob ◽  
Ola Hussein ◽  
Ibrahim Al-Ani ◽  
...  
Keyword(s):  
Bond Strength ◽  
Concrete Specimen ◽  
Light Weight ◽  
Reinforcing Bars ◽  
Conventional Concrete ◽  
Bond Behavior ◽  
Pull Out ◽  
Specimen Width ◽  
Light Weight Concrete ◽  
The Relationship

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%)).

Influence of Test Configuration on Bond Strength of GFRP Bars

2019 ◽  
Vol 292 ◽  
pp. 217-223 ◽  
Author(s):  
Ondřej Janus ◽  
Frantisek Girgle ◽  
Vojtech Kostiha ◽  
Petr Štěpánek ◽  
Pavel Sulak
Keyword(s):  
Bond Strength ◽  
Concrete Cover ◽  
Silica Sand ◽  
Beam Test ◽  
Bond Behaviour ◽  
Test Configuration ◽  
Gfrp Bars ◽  
Pull Out ◽  
Frp Reinforcement ◽  
Gfrp Reinforcement

It is well-known that test configuration affects bond behaviour of steel reinforcement, but this effect has not yet been sufficiently quantified when using FRP reinforcement. This paper presents partial results from an ongoing experimental programme that deals with the bond strength of GFRP bars with concrete, with regards to the effect of the surface treatment of the rebars and test configuration. A modified beam test is presented in this study along with a pull-out test with an eccentric bar placement. The bond strength of GFRP reinforcement with sand-coated treatment using silica sand and ribbed type with milled ribs was tested. The sand-coated bars exhibit different bond behaviour compared to the ribbed ones due to different forces transfer from the reinforcement to the concrete. Thickness of the concrete cover layer also has a significant effect on the bond behaviour of the reinforcement.

Pull-Out Tests of Deformed Bars from Ferrous Mill Tailing Concrete

2013 ◽  
Vol 477-478 ◽  
pp. 697-700
Author(s):  
Yan Zheng ◽  
Hong Zhen Kang ◽  
Guang Qi Wang
Keyword(s):  
Technical Support ◽  
Building Structures ◽  
Structural Concrete ◽  
Bond Behavior ◽  
Ordinary Concrete ◽  
Bonding Performance ◽  
Pull Out ◽  
Steel Bars ◽  
Mill Tailing

For application of FMT (ferrous mill tailing) to structural concrete, it is urgent need to study the bond behavior of reinforced bars with FMT concrete. In this paper, 72 pull-out tests of HRB335 steel bars from FMT concrete were carried out. The test phenomena and various factors influence on bond behavior were obtained. The results show that the bonding performance between deformed bars and FMT concrete is approximate to that of deformed bars and ordinary concrete. The results should provide technical support for application of FMT concrete in building structures.

scholarly journals Bond Behaviour Between Reinforcing Bars and Geopolymer Concrete By Using Pull-out Test

2019 ◽  
Vol 280 ◽  
pp. 04008
Author(s):  
Ratni Nurwidayati ◽  
Januarti Ekaputri ◽  
Triwulan ◽  
Priyo Suprobo
Keyword(s):  
Bond Strength ◽  
Sodium Hydroxide ◽  
Concrete Cover ◽  
Raw Material ◽  
Maximum Diameter ◽  
Geopolymer Concrete ◽  
Bond Behaviour ◽  
Reinforcing Bar ◽  
Pull Out ◽  
Bar Diameter

This paper presents the effect of the reinforcing bar diameter (db) and concrete cover thickness to reinforcing bar diameter ratio (c/db) to the bond strength between reinforcing bar and geopolymer concrete by using the experimental pull-out test. The mass ratio of sodium hydroxide (NaOH) to sodium silicate (Na2SiO3) was 2.5 with an 8 M concentration of sodium hydroxide were used in this research. Class F fly ash from Suralaya Power Station, Banten, Indonesia was used as raw material to produce geopolymer concrete. The maximum diameter of coarse aggregate was 10 mm. The result indicated that the maximum pull-out load on reinforcing bar diameter of 16 mm was higher than the diameter of 13 mm. The pull-out failure occurred on the ratio of c/db more than equal of 4.3. The bond strength increased as the ratio of c/db increased, up to 4.3. However, more than 4.3 was the insignificant effect.

Experimental study on the bond behavior between CFRP plates and steel substrates under fatigue loading

2019 ◽  
Vol 176 ◽  
pp. 107266 ◽  
Author(s):  
Hai-Tao Wang ◽  
Gang Wu ◽  
Yu-Yang Pang ◽  
Jia-Wei Shi ◽  
Habeeb Muhammad Zakari
Keyword(s):  
Experimental Study ◽  
Fatigue Loading ◽  
Bond Behavior ◽  
Steel Substrates
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