Experimental study of bond behaviour between concrete and FRP bars using a pull-out test

2009 ◽  
Vol 40 (8) ◽  
pp. 784-797 ◽  
Author(s):  
Marta Baena ◽  
Lluís Torres ◽  
Albert Turon ◽  
Cristina Barris
Keyword(s):  
Experimental Study ◽  
Bond Behaviour ◽  
Pull Out ◽  
Frp Bars

scholarly journals EXPERIMENTAL STUDY OF THE INFLUENCE OF ADHESIVE PROPERTIES AND BOND LENGTH ON THE BOND BEHAVIOUR OF NSM FRP BARS IN CONCRETE

2016 ◽  
Vol 22 (6) ◽  
pp. 808-817 ◽  
Author(s):  
Lluís TORRES ◽  
Ibrahim Attia SHARAKY ◽  
Cristina BARRIS ◽  
Marta BAENA
Keyword(s):  
Bond Length ◽  
Load Capacity ◽  
Experimental Studies ◽  
Adhesive Properties ◽  
Bond Behaviour ◽  
Near Surface ◽  
Bond Performance ◽  
Pull Out ◽  
Key Factor ◽  
Frp Bars

The near-surface mounted (NSM) fibre reinforced polymer (FRP) technique is a relatively recent system for strengthening concrete structures. Bond is a key factor in its behaviour, and is affected by many factors whose influence can only be tested through experimental studies. In this study, the modified pull-out test was used to study the effect of epoxy properties and bond length on the behaviour of NSM FRP bars. Three epoxy types, two FRP materials (carbon and glass) and four bond lengths (6db, 12db, 24db and 30db) are used. The load capacity, slips at the loaded end and free end and average bond stress are all analysed. The test results indicate that the role of epoxy properties appear to be a key factor in bond performance in the NSM FRP strengthening technique, and that their effect varies depending on bond length and FRP properties.

scholarly journals Bond load-slip behaviour of FRP bars in recycled-aggregate concrete

2020 ◽  
Vol 323 ◽  
pp. 01002
Author(s):  
Ahmed Godat ◽  
Ebtesam Alghafri ◽  
Noura AlTamimi ◽  
Hamda Aljaberi ◽  
Shaima Aldaweela
Keyword(s):  
Concrete Strength ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Experimental Program ◽  
Bond Behaviour ◽  
Aggregate Concrete ◽  
Pull Out ◽  
The Impact ◽  
Frp Bars

This study presents an experimental program conducted to investigate the bond strength of FRP bars in recycled-aggregate concrete compared to the one in normal-aggregate concrete for the improved evaluation of results. The experimental program contains thirty six specimens tested using direct pull-out test. In this study, glass, carbon and basalt FRP bars are used with 12 mm diameter and bar bond lengths of 5d, where d is the bar diameter. The FRP bars are casted in different recycled-aggregate concrete strengths of 30, 45 and 60 MPa. The behaviour of bars in normal-aggregate concrete strength of 30 MPa is used as a benchmark and its behaviour is compared with the ones in the recycled-aggregate concrete. The impact of the concrete strength considered is identified based on the gain in the bond behaviour. The experimental results demonstrate the prospect of the recycled aggregates applied as an alternative to normal aggregates in the FRP reinforced concrete. In addition, the use of the recycled aggregate increases the bearing friction behaviour between the FRP bars and concrete.

Auszugverhalten von Schaftfräsern*/Pull-out behavior of end mills – Experimental study on different clamping devices with various clamping mechanisms

2018 ◽  
Vol 108 (05) ◽  
pp. 353-358
Author(s):  
E. Abele ◽  
F. Ali ◽  
M. Berger
Keyword(s):  
Experimental Study ◽  
Test Bench ◽  
Mechanical Load ◽  
Mechanisms Of Action ◽  
Heavy Duty ◽  
Press Fit ◽  
Pull Out ◽  
The Press ◽  
End Mills ◽  
Tool Position

Aus Schwerzerspanung und Turbinenschaufelfertigung ist bekannt, dass Werkzeuge aus dem Spannfutter ausgezogen werden. Die veränderte Werkzeugposition führt zur Abweichung von den vorgegebenen Toleranzen und einer geringeren Fertigungsqualität oder Beschädigung des Werkstücks. Der Artikel untersucht das Auszugsverhalten verschiedener Spannfutter. Mit einem Prüfstand können die Einflüsse der mechanischen Belastung und der Klemmlänge auf die Haltekraft im Pressverband betrachtet und die Wirkmechanismen beim Auszug des Werkzeuges aus dem Spannfutter sensorisch ermittelt werden.   From heavy-duty cutting and turbine blade manufacturing it is known that tools pull out from chucks. A change in tool position leads to deviations from tolerance and decreases manufacturing quality or damages the workpiece. This article explores the extension behavior of different chucks on a specifically designed test bench. This allows determining how mechanical load and clamping length influence the holding force in the press fit and what mechanisms of action affect the extraction of the tool from the chuck.

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>

scholarly journals Experimental study on flexural behavior of ECC-concrete composite beams reinforced with FRP bars

2019 ◽  
Vol 208 ◽  
pp. 454-465 ◽  
Author(s):  
Wenjie Ge ◽  
Ashraf F. Ashour ◽  
Dafu Cao ◽  
Weigang Lu ◽  
Peiqi Gao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Composite Beams ◽  
Flexural Behavior ◽  
Frp Bars

TM3-10 National survey and experimental evaluation of commonly used external ventricular drain (EVD) securement methods in a porcine model; recommendations to improve practise

2019 ◽  
Vol 90 (3) ◽  
pp. e17.3-e16
Author(s):  
D Akarca ◽  
A Durnford ◽  
F Ewbank ◽  
J Hempenstall ◽  
A Sadek ◽  
...  
Keyword(s):  
Experimental Study ◽  
Experimental Model ◽  
Experimental Evaluation ◽  
Porcine Model ◽  
External Ventricular Drain ◽  
Insertion Site ◽  
Trial Data ◽  
Significant Morbidity ◽  
Pull Out ◽  
Catheter Fracture

ObjectivesExternal ventricular drain (EVD) dislodgement is common and can lead to significant morbidity and mortality. UK trial data suggests dislodgement as high as 12%. This study aimed to establish the range of methods used nationally and determine the most secure method in a porcine model.DesignSurvey and experimental study.Subjects23 neurosurgical units surveyed. Porcine cadaver experimental model.MethodsSurvey distribution was made through the British Neurosurgical Trainee Research Collaborative. 15 securement methods were tested on the porcine model and peak pull-out force before EVD failure was measured. Failure was defined as catheter displacement 1 cm from the insertion site, catheter fracture or suture fracture.ResultsNationally, five EVD securement methods were in common use. There were considerable differences in peak pull-out force between methods. The most secure methods were a construct consisting of anchoring suture, further multiple sutures around a coil of catheter followed by either a soft (25.85N, 95% CI 24.95 N-26.75N) or hard plastic flange (29.05N, 95% CI 25.69 N-32.41N). Individually, anchoring sutures, soft flanges, VentriFix and staples were least secure, whilst multiple sutures and hard flanges were most secure.ConclusionsAn anchoring suture followed by a coil of catheter and a flange is the most secure method for securing EVDs, withstanding up to 8.2 times the force of a single anchoring suture. It is easily employed and may decrease the likelihood of EVD dislodgement and associated complications.

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