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.

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.

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%)).

Bond behaviour of chemically prestressed textile reinforced concrete

2019 ◽  
Author(s):  
Katarzyna Zdanowicz ◽  
Boso Schmidt ◽  
Hubert Naraniecki ◽  
Steffen Marx
Keyword(s):  
Reinforced Concrete ◽  
Bond Strength ◽  
Crack Width ◽  
Research Programme ◽  
Textile Reinforced Concrete ◽  
Self Compacting Concrete ◽  
Bond Behaviour ◽  
Bond Slip ◽  
Laser Sensors ◽  
Pull Out

<p>The bond behaviour of concrete specimens with carbon textile reinforcement was investigated in the presented research programme. Pull-out specimens were cast from self-compacting concrete with expansive admixtures and in this way chemical prestress was introduced. The aim of the research was to compare bond behaviour between prestressed specimens and non-prestressed control specimens. During pull-out tests, the pull-out force and notch opening were measured with a load cell and laser sensors. Further, bond - slip and pull-out force - crack width relationships were drawn and compared for prestressed and non-prestressed specimens. Chemically prestressed specimens reached 24% higher bond strength than non-prestressed ones. It can be therefore concluded, that chemical prestressing positively influences the bond behaviour of concrete with textile reinforcement and thus better utilisation of its properties can be provided.</p>

Study on Bond Properties of Textile Reinforced Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 334-340
Author(s):  
Wen Ling Tian ◽  
Li Min Zhang
Keyword(s):  
Reinforced Concrete ◽  
Epoxy Resin ◽  
Concrete Strength ◽  
Practical Method ◽  
Bond Properties ◽  
Textile Reinforced Concrete ◽  
Bond Behavior ◽  
Fine Grained ◽  
Pull Out ◽  
Concrete Matrix

Textile reinforced concrete (TRC) allows the light weight structures and offers a high effectiveness of the reinforcement by using continuous yarns. The study on the bond behavior between textile and concrete matrix is significant for the development of computational methods that analyze the textile reinforced concrete. The paper analyzes the bonding constitutive model of TRC and the bonding mechanism that the stress is transferred from fine concrete to textile, pointing out quadruple linear model can accurately reflect the bond behavior between fiber and concrete, illustrates the main influences on bond between the fine grained matrix and fabrics based on the pull-out test, the result reveals that with initial bond length increasing, the maximum pull force increases, and increasing concrete strength and improving workability of concrete matrix, epoxy resin impregnating and sand covering of textile as well as prestressing textile can increase the bond strength between textile and concrete. Finally the paper proposes that epoxy resin impregnating and 0.15 ~ 0.30mm sand covering of textile can be used as a practical method of improving bond properties in the engineering.

Study on the Effect of Bond-Anchoring Factor on Bond Behavior between Deformed Bar and Shale Ceramic Concrete

2011 ◽  
Vol 403-408 ◽  
pp. 444-448
Author(s):  
Wei Jun Yang ◽  
Jie Yu ◽  
Yan Wang
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Anchorage Length ◽  
Bond Behavior ◽  
Pull Out ◽  
Practical Project ◽  
Deformed Bar

In this paper, the effect of bond-anchoring factor on bond behavior between deformed bar and shale ceramic concrete was analyzed by four groups of pull-out tests with different anchorage length. And three reinforced concrete pull-out tests used for comparative analysis were prepared at the same time. We obtained a series of experimental data and based on these data .A more accurate formula was summed up. This formula has a high value in guiding the practical project to choose the anchorage length.

scholarly journals The Comparison of Bond Strength between Geopolymer Concrete and OPC Concrete for Plain Reinforcing Bars

2018 ◽  
Vol 159 ◽  
pp. 01017 ◽  
Author(s):  
Nuroji ◽  
Daniel Herdian Primadyas ◽  
Ilham Nurhuda ◽  
Muslikh
Keyword(s):  
Bond Strength ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Reinforcing Bars ◽  
Normal Concrete ◽  
Steam Power ◽  
Bond Behavior ◽  
Pull Out ◽  
Concrete Blocks ◽  
Class F Fly Ash

This paper describes the research on bond behavior of plain reinforcing bars in geopolymer and normal concrete. The geopolymer concrete in this research was made of class F fly ash taken from Tanjung Jati Electric Steam Power Plant (PLTU) with Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) as alkaline activator, added in the mixture. The effect of bar size was studied by varying the bar diameter in range 10 mm to 19 mm. Each bar was casted in the center of concrete blocks made of geopolymer as well as normal concrete. Pull-out tests were carried out to the specimens that have reached 28 days of age. The test results show that the bond behavior of geopolymer concrete differs substantially from normal concrete, where geopolymer concrete has a higher bond strength when compared to normal concrete with identical concrete strengths.

Experimental Study on Anchoring Bond Behavior of Pre-Tensioned Prestressed Concrete Beams with Corroded Steel Strands

2011 ◽  
Vol 243-249 ◽  
pp. 304-307
Author(s):  
Fu Min Li ◽  
Xiao Fei Shi ◽  
Fu Ping Jia
Keyword(s):  
Experimental Study ◽  
Bond Strength ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Load Test ◽  
Structural Behavior ◽  
Short Term ◽  
Bond Behavior

To study the influence of steel strands corrosion on the bond behavior for anchoring of pre-tensioned prestressed concrete beams, nine specimens were fabricated. Of which, 5 beams were mixed with salt and set in different places to be corroded in different intensity for 13 months. Then the load test was held to all the 9 specimens and the load-slip curves were obtained. The results show that under the condition of no corrosion crack, the short-term anchoring bond strength of pre-tensioned prestressed concrete beams increases for the steel strands corrosion. Because the tension behavior of steel strands deteriorates remarkably even if the corrosion is slight, which is the dominant cause for the degradation of fundamental structural behavior, the influence of steel strands corrosion on the bond behavior for anchoring may be ignored.

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