scholarly journals Experimental Study on Bond-Slip Behavior between H-Shaped Steel and Gypsum Cover in SGFCG

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Tao Sun ◽  
Kejian Ma ◽  
Zhihua Chen ◽  
Jin Chen ◽  
Yuhao Zhu
Keyword(s):  
Bond Strength ◽  
Compression Strength ◽  
Constitutive Relationship ◽  
Test Results ◽  
Bond Slip ◽  
Main Factors ◽  
Cover Thickness ◽  
Average Bond ◽  
Push Out

Nine push-out specimens of H-shaped steel with gypsum cover (HSG) are designed to study the bond-slip behavior between steel and gypsum in steel grid frame filling with cast-in-situ gypsum (SGFCG). Three main factors including gypsum compression strength (fcu), gypsum cover thickness (Cs), and steel-gypsum connected length (la) are considered. It is shown by the test results that the ultimate average bond strength is within [0.333–0.456] MPa, and the residual strength is about 90–98% of the ultimate strength. Both gypsum cover thickness and steel-gypsum connected length have evident influence on the bond strength, while the effect of gypsum compression strength is not obvious. Based on the test data, the formulas of average bond strength characteristics (τs¯, τu¯, and τr¯) and slip characteristics (Su and Sr) are established by statistical fitting. Furthermore, the bond-slip constitutive relationship (τ¯−S) is recommended.

scholarly journals Research on bond–slip performance between pultruded glass fiber-reinforced polymer tube and nano-CaCO3 concrete

2020 ◽  
Vol 9 (1) ◽  
pp. 637-649 ◽  
Author(s):  
Zhan Guo ◽  
Qingxia Zhu ◽  
Wenda Wu ◽  
Yu Chen
Keyword(s):  
Bond Strength ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Bond Slip ◽  
Ordinary Concrete ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Push Out

AbstractThe article describes an experimental study on the bond–slip performance between the pultruded glass fiber-reinforced polymer (GFRP) tube and the nano-CaCO3 concrete. Taking the nano-CaCO3 concrete strength and GFRP tube thickness as primary parameters, nine specimens were designed and tested to study the influence of these parameters on the bond strength of the specimens. Besides, three specimens filled with the ordinary concrete were also tested by using the push-out tests to make comparisons with the bond performance of the specimens filled with nano-CaCO3 concrete. A total of four push-out tests were conducted on each specimen. The experimental results indicate that there are two types of axial load–slip curves for each specimen in four push-out tests. Moreover, comparison of the results of the push-out tests in the same direction shows that the bond failure load of the specimen decreases with the increase in the number of push-out tests. Based on the analysis of the test results, it is shown that the bond performance between the GFRP tube and the nano-CaCO3 concrete is better than that between the GFRP tube and the ordinary concrete. Furthermore, as the nano-CaCO3 concrete strength increases, the bond strength of the specimens decreases, indicating that the concrete strength has a negative effect on the bond strength. When the nano-CaCO3 concrete strength is relatively smaller (C20), the bond strength of the specimens decreases with the increase in the thickness of the GFRP tube. However, when the nano-CaCO3 concrete strength is relatively larger (C30 and C40), the bond strength of the specimens increases as the thickness of the GFRP tube increases.

Bond of Steel Bars to Masonry Mortar Joints: Test Results and Analytical Modelling

2017 ◽  
Vol 747 ◽  
pp. 319-325 ◽  
Author(s):  
Matteo Maragna ◽  
Cristina Gentilini ◽  
Giovanni Castellazzi ◽  
Christian Carloni
Keyword(s):  
High Strength ◽  
Experimental Tests ◽  
Analytical Investigation ◽  
Masonry Walls ◽  
Test Results ◽  
Bond Slip ◽  
Pull Out ◽  
Steel Bars ◽  
Masonry Mortar

In this paper, the preliminary results of a series of pull-out tests conducted on mortar cylinders with embedded bars are presented. The bars are made of high strength stainless steel and are of helical shape to increase mechanical interlocking with the surrounding mortar. Usually, such bars are employed in situ to realize structural repointing in the case of fair-faced masonry walls. To this aim, they are inserted in the mortar bed joints of masonry for providing tensile strength to the walls and with the function of crack stitching. The aim of the present experimental tests is to determine the bond-slip relationship for bars embedded in masonry. Firstly, pull-out tests are conducted on mortar cylinders considering different embedded lengths of the bars. Further tests are on-going on masonry specimens with bars embedded in the mortar joints. An analytical investigation is also carried out for the interpretation of the pull-out test results.

scholarly journals Effect of cement type and thickness on push-out bond strength of fiber posts

2018 ◽  
Vol 12 (4) ◽  
pp. 277-282
Author(s):  
Farzaneh Farid ◽  
Khadijeh Rostami ◽  
Sareh Habibzadeh ◽  
MohammadJavad Kharazifard
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Test Results ◽  
Resin Cements ◽  
Fiber Posts ◽  
Significant Difference ◽  
Root Dentin ◽  
Group 2 ◽  
Self Etch ◽  
Push Out

Background. This study investigated the effect of the thickness of two resin cements on push-out bond strength of fiber posts to root dentin. Methods. Sixty decoronated single-rooted teeth were endodontically treated. The specimens were then randomly allocated to two groups (n=30); group 1: drill size 90 w, matching the size of fiber posts used; group 2: drill size 110, larger than the posts. The specimens in each group were divided into 2 subgroups (n=15); subgroup SE, in which the posts were cemented with self-etch Panavia F2.0 and subgroup SA, in which self-adhesive Panavia cement was used. After 72 hours, 2 slices with 1 mm of thickness were prepared from the mid-root of each specimen. Push-out bond strength test was performed in a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and t-test. Results. The mean bond strengths of the posts cemented in matched-size spaces for SE and SA groups were 4.02±1.6 and 4.12±2.3 MPa, respectively. For posts cemented in oversized spaces, the values were 4.9±2.3 and 2.8±1.3 MPa, respectively. In matched-size spaces, there was no significant difference between the two groups. Conclusion. The results of this study suggested that increasing the cement thickness would reduce the bond strength of fiber posts to root dentin when self-adhesive cements are used; however, self-etch adhesives were not affected.

scholarly journals Regression Analysis of Bond Parameters between Corroded Rebar and Concrete Based on Reported Test Data

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
H. J. Zhou ◽  
Y. F. Zhou ◽  
Y. N. Xu ◽  
Z. Y. Lin ◽  
F. Xing ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Bond Strength ◽  
Crack Width ◽  
Experimental Tests ◽  
Test Results ◽  
Bond Slip ◽  
Regression Effect ◽  
Pull Out ◽  
Maximum Crack ◽  
Best Fit

Reinforcement corrosion is a major cause of degradation in reinforced concrete structures. The fragile rust layer and cracking and spalling of the cover caused by splitting stress due to rust expansion can alter bond behaviors significantly. Despite extensive experimental tests, no stochastic model has yet incorporated randomness into the bond parameters model. This paper gathered published experimental data on the bond-slip parameters of pull-out specimens and beam-end specimens. Regression analysis was carried out to identify the best fit of bond strength and the corresponding slip value in the context of different corrosion levels from the recollected test results. An F-test confirmed the regression effect to be significant. Residual data were also analyzed and found to be well described by a normal distribution. Crack width data of the tested specimens were also collected. A regression analysis of the bond strength and maximum crack width was carried out given the comparative simplicity of measuring crack width versus rebar area loss. Results indicate that maximum crack width can also be used to predict bond strength degradation with similar variation magnitude.

scholarly journals Bond Behavior between Steel Rebar and RCA Concrete after Exposure to Elevated Temperatures

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Wanjie Zou ◽  
Jiongfeng Liang ◽  
Dawei Liu ◽  
Guangwu Zhang
Keyword(s):  
Bond Strength ◽  
Elevated Temperatures ◽  
Coarse Aggregate ◽  
Test Results ◽  
Modified Model ◽  
Bond Slip ◽  
Bond Behavior ◽  
Steel Rebar ◽  
Exposure Temperature ◽  
Increasing Temperature

To explore the bond behavior between steel rebar and recycled coarse aggregate (RCA) concrete after exposure to elevated temperatures, an experimental study was carried out. The results demonstrated that the bond strength of RCA concrete pullout specimens decreased greatly with increasing temperature. As the exposure temperature elevated, the slope of the ascending portion of the bond-slip curves gradually declined, and the descending portion of the curves tended to flatten. A modified model was developed to predict the bond strength between RCA concrete and steel rebar after exposure to elevated temperature, and the predicted results showed a very good fit in the experimental test results. Besides, the proposed bond-slip relations for steel rebar in RCA concrete after elevated temperatures showed satisfactory agreement with test results.

Finite Element Analysis of the Pull-Out Specimens of Steel Reinforced Lightweight Concrete

2012 ◽  
Vol 166-169 ◽  
pp. 514-519
Author(s):  
Jian Wen Zhang ◽  
Shi Hui Guo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Lightweight Concrete ◽  
Constitutive Relationship ◽  
Test Results ◽  
Concrete Element ◽  
Element Analysis ◽  
Bond Slip ◽  
Spring Element ◽  
Pull Out

Finite element analysis method of steel reinforced lightweight concrete pull-out specimens is exploded based on the test results. Spring element and local bond slip constitutive relation are introduced in analysis so as to consider the interfacial bond-slip between steel and lightweight concrete. Element tributary area and flange or web position should be taken into account in order to confirm the spring element real constant. Analysis results indicate that specimens bearing capacity and deformation can be well simulated adopting the stated method and constitutive relationship.

scholarly journals Finite element analysis on the bond behavior of steel bar in salt–frost-damaged recycled coarse aggregate concrete

2021 ◽  
Vol 60 (1) ◽  
pp. 853-861
Author(s):  
Tian Su ◽  
Ting Wang ◽  
Haihe Yi ◽  
Rui Zheng ◽  
Yizhe Liu ◽  
...  
Keyword(s):  
Bond Strength ◽  
Concrete Cover ◽  
Bond Slip ◽  
Bond Behavior ◽  
Steel Bar ◽  
Calculation Results ◽  
Cover Thickness ◽  
Bar Diameter ◽  
Good Agreement ◽  
Ultimate Bond Strength

Abstract In this article, the ABAQUS finite element software is used to simulate the bond behavior of the steel bar in salt–frost-damaged recycled coarse aggregate concrete, and the influence of the steel bar diameter and the concrete cover thickness on the bond strength is investigated. The result shows that the calculated bond–slip curve is in good agreement with the experimental bond–slip curve; the mean value of the ratio of the calculation results of ultimate bond strength to the experiment results of ultimate bond strength is 1.035, the standard deviation is 0.0165, and the coefficient of variation is 0.0159, which proves that the calculation results of the ultimate bond strength are in good agreement with the experimental results; with the increase of steel bar diameter and the concrete cover thickness, the ultimate bonding strength of RAC and steel increases; the calculation formulas for the ultimate bond strength of specimens with different steel bar diameters (concrete cover thickness) after different salt–frost cycles are obtained.

scholarly journals Bond Performance of Sand-Coated BFRP Bars to Concrete

2019 ◽  
Vol 8 (10) ◽  
pp. 1330-1335
Keyword(s):  
Bond Strength ◽  
Test Results ◽  
Basalt Fibre ◽  
Bond Failure ◽  
Bond Behaviour ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Average Bond

This paper presents an experimental study on the bond behaviour of sand-coated basalt fibre reinforced polymer (BFRP) bars and conventional steel bars of 10mm- diameter. The bond strength of these bars were determined according to ASTM D7913/D7913M-14 standards. The pullout specimens consisted of BFRP bars embedded in concrete cubes (200mm on each side) with the compressive strength of 40MPa were constructed. The pullout test results contain the bond failure mode, the average bond strength , the slip at the free and loaded end, and the bond stress-slip relationship curves.The test results showed that the bond strength of sand-coated BFRP bars was about 70% that of the steel bars.

Bond strength of concrete plugs embedded in tubular steel piles under cyclic loading

2006 ◽  
Vol 33 (2) ◽  
pp. 111-125 ◽  
Author(s):  
Abolghasem Nezamian ◽  
Riadh Al-Mahaidi ◽  
Paul Grundy
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Bond Strength ◽  
Steel Tube ◽  
Test Results ◽  
Pull Out ◽  
Steel Piles ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
Push Out

Investigation of the load transfer of concrete plugs to tubular steel piles subjected to tension and compression and cyclic loading has been conducted at Monash University over the past 3 years. The work presented in this paper reports on the results of the combination of pull-out, push-out, and cyclic loading tests carried out on 15 steel tube specimens filled partially with reinforced concrete with variable lengths of embedment. The pull-out force was applied through steel reinforcing bars embedded in the concrete plug, and push-out forces were applied through a thick top circular plate on the top of the concrete plug. Test results included the cyclic loading, ultimate pull-out and push-out forces, slip of concrete plugs, and longitudinal and hoop strains along the piles for some specimens. The tests clearly showed that average bond strength significantly exceeds expectations and is higher than the results of previous investigations using plugs without reinforcement. The test results also indicated that cyclic loading tests reduced the bond strength due to the accumulation of damage to the plug–pile interface. The push-out and pull-out tests conducted under symmetric cyclic loading demonstrated that slip between the concrete plug and the steel tube increased with repeated loading, and the rate of slip growth increased with an increase in the peak load.Key words: tubular steel pile, reinforced concrete plug, bond, cyclic loading.

scholarly journals SERVICEABILITY ANALYSIS OF FLEXURAL REINFORCED CONCRETE MEMBERS / LENKIAMŲJŲ GELŽBETONINIŲ ELEMENTŲ TINKAMUMO ANALIZĖ

2012 ◽  
Vol 18 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Gintaris Kaklauskas ◽  
Viktor Gribniak ◽  
Ronaldas Jakubovskis ◽  
Eugenijus Gudonis ◽  
Donatas Salys ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Numerical Procedure ◽  
Reinforced Concrete Beams ◽  
Crack Model ◽  
Test Results ◽  
Rigid Plastic ◽  
Bond Slip ◽  
Concrete Members ◽  
Discrete Crack ◽  
Average Bond

The paper presents a simple discrete crack model for analyzing the deformation and crack width of reinforced concrete beams. The model is based on a non-iterative algorithm and uses a rigid-plastic bond-slip law and elastic properties of materials. Curvatures and crack widths predicted by the proposed technique were checked against the test results of six experimental beams, reported by the authors and other investigators. The article also proposes and discusses a numerical procedure for deriving the average bond stress with reference to the test data. Serviceability analysis resulted in a reasonable agreement on the test measurements. Santrauka Straipsnyje pateikiamas supaprastintas diskrečiųjų plyšiu modelis gelžbetoninių sijų deformacijų ir plyšio pločio analizei. Modelis pagrįstas neiteraciniu algoritmu, remiantis standžiai plastiniu sukibimo desniu ir tampriosiomis medžiagų savybėmis. Remiantis skirtingų autorių atliktais eksperimentiniais duomenimis, modelis patikrintas skaičiuojant gelžbetoninių sijų kreivius ir plyšio pločius. Apskaičiuotos kreivių ir plyšio pločių reikšmės gana tiksliai sutapo su eksperimentiniais rezultatais. Taip pat pasiūlytas originalus vidutinių sukibimo įtempių apskaičiavimo metodas, remiantis eksperimentiniais lenkiamujų gelžbetoninių sijų bandymo rezultatais.

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