scholarly journals Bond strength of epoxy coated bar splices confined with nominal lateral reinforcement

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Krishnamurthy Pandurangan ◽  
Gangolu Rao
Keyword(s):  
Bond Strength ◽  
Primary Objective ◽  
Reduction Factor ◽  
Full Scale ◽  
Epoxy Coating ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Bar Test ◽  
Lateral Reinforcement ◽  
Constant Moment

AbstractFusion bonded epoxy coating is one of the methods used to protect steel against corrosion. The primary objective of this research reported in this paper is to evaluate the bond strength of epoxy coated bar splices confined with lateral reinforcement. Six full scale beams specimens, designed to fail in bond- splitting mode, were tested in positive bending. Each beam was reinforced with bars spliced in the constant moment region at mid span. The main variables were the amount of transverse reinforcement in the splice region and the coating to the bar. Test results indicate that transverse reinforcement improves the bond strength of coated bars and the ductility of the beams. The bond strength of coated bars is 93%, 72% and 59% of uncoated bars for confinement indices of 1.8, 1.4 and 1.26 respectively. Moreover, a bond reduction factor of 1.35 is suggested for use in code in place of 1.5,when the confinement index is greater than 1.4.

Investigation of bond between lap-spliced steel bar and self-compacting concrete: The role of silica fume

2010 ◽  
Vol 37 (3) ◽  
pp. 420-428 ◽  
Author(s):  
Mehmet Karatas ◽  
Kazim Turk ◽  
Zulfu C. Ulucan
Keyword(s):  
Bond Strength ◽  
Silica Fume ◽  
Full Scale ◽  
Reinforcing Bars ◽  
Self Compacting Concrete ◽  
Normal Concrete ◽  
Steel Bar ◽  
Normalized Bond Strength ◽  
Constant Moment

In this study, normal concrete (NC) and four types of self-compacting concrete (SCC), in which cement was partially replaced by 5%, 10%, 15%, and 20% of silica fume (SF), were used to evaluate the effect of SF content on the bond strength of tension lap-spliced bars embedded in NC and SCC specimens. Therefore, 15 full-scale beam specimens (2000 × 300 × 200 mm3) were tested and 20 mm reinforcing bars were used with a 300-mm splice length as tension reinforcement. Each beam was designed with bars spliced in a constant moment region at midspan. It was found that the bond strength of the reinforcement embedded in SCC beams was higher than that of the reinforcement in NC beams, whilst the bond strength increased with increase in the replacement of cement by SF from 5% to 10%. Moreover, the beam specimens produced from SCC containing 5% SF had the highest normalized bond strength of 1.07 followed by SCC beams with 10% SF, 15% SF, NC beams, and 20% SF.

scholarly journals Bond Strength of Fusion Bonded Epoxy-Coated Reinforcement in Concrete

2019 ◽  
Vol 5 (3) ◽  
pp. 255
Author(s):  
G M Sadiqul Islam ◽  
Ehsan Ahmed ◽  
Md. Sabbir Hossain ◽  
S. M. Sharif Uddin
Keyword(s):  
Bond Strength ◽  
Concrete Strength ◽  
Epoxy Coating ◽  
Test Results ◽  
Reinforced Concrete Structure ◽  
Reinforcing Bars ◽  
Strength Based ◽  
Modification Factor ◽  
Bar Diameter ◽  
Bond Characteristics

Fusion-bonded epoxy-coated steel is expected to extend the service life of the reinforced concrete structure in chloride-laden environments. However, the effect of coating on the bond-strength between rebar and concrete is not well understood yet. This research, therefore, studied the effect of epoxy-coating on the bond characteristics of reinforcing bars in concrete. The bond characteristics were assessed through pullout test considering variables viz. concrete strength, embedded length and bar diameter. The load was applied to reinforcing bars embedded in concrete until bond strength between the bar and concrete exceeded. Bond strength of epoxy-coated bars was compared with that of the uncoated bars. It was found that epoxy-coating reduced the bond strength approximately 25% for Ø20mm bar and 12% for Ø16mm and Ø12mm bar. As with uncoated bar, bond strength of coated bars were also increased with concrete strength. However, the bond strength ratio between coated and uncoated bars was found almost independent of concrete strength. Based on the test results, a development length modification factor of 1.33 is proposed for Ø20mm bar and 1.15 for Ø12mm and Ø16mm bar to compensate the bond strength reduction due to the epoxy coating.

Behavior of headed shear studs in stub–girder stub assemblages

1986 ◽  
Vol 13 (1) ◽  
pp. 106-115
Author(s):  
T. W. K. Chan ◽  
T. Rezansoff ◽  
M. U. Hosain
Keyword(s):  
Key Words ◽  
Reduction Factor ◽  
Shear Capacity ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Single Row ◽  
Full Development ◽  
Modification Factor ◽  
Headed Stud ◽  
Stud Connector

The paper summarizes the results of push-off tests conducted on 42 end stub assemblages. Written for conventional composite construction, the current Canadian Standards Association (CSA) standard on stud connectors offers little guidance for stub–girder design. A stud spacing of four times the stud diameter (the CSA requirement) does not appear to be adequate for a full development of the potential shear capacity of a stud connector in the stub–girder system. The required minimum stud spacing appears to be between five and six times the stud diameter for the case of 13 mm studs. Moreover, the CSA-recommended shear capacity of stud connector should be reduced to reflect the effect of prying forces. A modification factor of 0.9 is suggested for a 13 mm diameter stud connector. Test results for specimens with 19 mm studs indicated a further decrease in the shear capacity. However, a definite recommendation is postponed pending further tests.In addition to prying forces, stud configuration and spacing and the amount and location of transverse reinforcement must also be taken into account in determining the shear capacity of a stud connector. For a connection with 13 mm studs arranged in a single row, a reduction factor equal to stud spacing divided by six times the stud diameter is suggested when the stud spacing is less than six times the stud diameter. For a connection with staggered studs, the corresponding factor is obtained by dividing the stud spacing by five times the stud diameter when the stud spacing is less than five times the stud diameter. Key words: headed stud, shear capacity, minimum stud spacing, prying force.

Bond Strength between Old and New Concretes with Focus on the Strengthening of Reinforced Concrete Columns - Slant Shear Test versus Double Sleeve Test

2017 ◽  
Vol 864 ◽  
pp. 324-329 ◽  
Author(s):  
E.M. Piancastelli ◽  
Aldo G. Magalhães ◽  
Fernando José Silva ◽  
M.A.P. Rezende ◽  
White J. Santos ◽  
...  
Keyword(s):  
Experimental Study ◽  
Linear Regression ◽  
Bond Strength ◽  
Shear Test ◽  
Concrete Columns ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Strength Tests ◽  
Existing Structure ◽  
Slant Shear

The purpose of this paper is to present the main aspects and results of an experimental study to determine the bond strength between the concrete of a column of an existing structure (old concrete) and the concrete that will be used in its strengthening project (new concrete). For the bond strength tests, a specimen was conceived, called Double Sleeve specimen. The bond strength results obtained from the tests using Double Sleeve specimens, called Double Sleeve Tests, were compared to the results obtained from using the Slant Shear Test. The values for the bond strength between the two concretes, obtained from the Double Sleeve Tests, were either below or above the values obtained from linear regression of the Slant Shear Test results, depending on the sleeve diameter and the ratio of transverse reinforcement used. This fact, enabled concludes that the Double Sleeve Test is the most appropriate test to evaluate the bond strength between concretes of columns strengthened.

Experimental study of the strength and durability of metal-composite high-pressure tanks

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 49-56 ◽  
Author(s):  
A. M. Lepikhin ◽  
V. V. Moskvichev ◽  
A. E. Burov ◽  
E. V. Aniskovich ◽  
A. P. Cherniaev ◽  
...  
Keyword(s):  
High Pressure ◽  
Strain State ◽  
Full Scale ◽  
Fracture Mechanisms ◽  
Metal Composite ◽  
Test Results ◽  
Stress Strain ◽  
Pneumatic Pressure ◽  
Stress Strain State ◽  
Composite Tank

The results of unique experimental studies of the strength and service life of a metal-composite high-pressure tank are presented. The goal of the study is to analyze the fracture mechanisms and evaluate the strength characteristics of the structure. The methodology included tests of full-scale samples of the tank for durability under short-term static, long-term static and cyclic loading with internal pneumatic pressure. Generalized test results and data of visual measurements, instrumental and acoustic-emission control of deformation processes, accumulation of damages and destruction of full-scale tank samples are presented. Analysis of the strength and stiffness of the structure exposed to internal pneumatic pressure is presented. The types of limiting states of the tanks have been established experimentally. Change in the stress-strain state of the tank under cyclic and prolonged static loading is considered. Specific features of the mechanisms of destruction of a metal-composite tank are determined taking into account the role of strain of the metal liner. The calculated and experimental estimates of the energy potential of destruction and the size of the area affected upon destruction of the tank are presented. Analysis of test results showed that the tank has high strength and resource characteristics that meet the requirements of the design documentation. The results of the experiments are in good agreement with the results of numerical calculations and analysis of the stress-strain state and mechanisms of destruction of the metal-composite tank.

Predicting Roof Diaphragm and Endwall Stiffness From Full-Scale Test Results of a Metal-Clad, Post-Frame Building

1992 ◽  
Vol 35 (3) ◽  
pp. 977-985 ◽  
Author(s):  
K. G. Gebremedhin ◽  
J. A. Bartsch ◽  
M. C. Jorgensen
Keyword(s):  
Full Scale ◽  
Test Results ◽  
Full Scale Test ◽  
Frame Building ◽  
Scale Test

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

Test results of full-scale high temperature superconductors cable models destined for a 36 kV, 2 kArms utility demonstration

2001 ◽  
Vol 357-360 ◽  
pp. 1241-1244 ◽  
Author(s):  
M. Däumling ◽  
C.N. Rasmussen ◽  
F. Hansen ◽  
D.W.A. Willén ◽  
O.E. Schuppach ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Superconductors ◽  
Full Scale ◽  
Test Results

Benchmarking of Truss Spar Vortex Induced Motions Derived From CFD With Experiments

2005 ◽  
Author(s):  
John Halkyard ◽  
Senu Sirnivas ◽  
Samuel Holmes ◽  
Yiannis Constantinides ◽  
Owen H. Oakley ◽  
...  
Keyword(s):  
Scale Up ◽  
Vertical Cylinder ◽  
Reynolds Numbers ◽  
Full Scale ◽  
Scale Model ◽  
Current Direction ◽  
Test Results ◽  
Helical Strakes ◽  
Truss Spar ◽  
Scale Data

Floating spar platforms are widely used in the Gulf of Mexico for oil production. The spar is a bluff, vertical cylinder which is subject to Vortex Induced Motions (VIM) when current velocities exceed a few knots. All spars to date have been constructed with helical strakes to mitigate VIM in order to reduce the loads on the risers and moorings. Model tests have indicated that the effectiveness of these strakes is influenced greatly by details of their design, by appurtenances placed on the outside of the hull and by current direction. At this time there is limited full scale data to validate the model test results and little understanding of the mechanisms at work in strake performance. The authors have been investigating the use of CFD as a means for predicting full scale VIM performance and for facilitating the design of spars for reduced VIM. This paper reports on the results of a study to benchmark the CFD results for a truss spar with a set of model experiments carried out in a towing tank. The focus is on the effect of current direction, reduced velocity and strake pitch on the VIM response. The tests were carried out on a 1:40 scale model of an actual truss spar design, and all computations were carried out at model scale. Future study will consider the effect of external appurtenances on the hull and scale-up to full scale Reynolds’ numbers on the results.

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