Analytical Study on Bond Characterization of Hybrid-Bonded FRP to Concrete Interfaces

2013 ◽  
Vol 405-408 ◽  
pp. 2528-2533
Author(s):  
Kang Liu
Keyword(s):  
Bond Strength ◽  
Analytical Study ◽  
Adhesive Bond ◽  
Slip Model ◽  
Interfacial Bond ◽  
Bond Slip ◽  
Bond Interface ◽  
Good Agreement

Pure adhesive bond of FRP to concrete is not only weak but also unreliable in a long term. This problem can be effectively overcome by a newly developed bond enhancement system the hybrid bonded FRP system (HB-FRP) in which small mechanical fasteners are used to augment the bond. In this paper, theoretical modeling is reported for characterization of the interfacial bond of the HB-FRP system. Local bond-slip model involving adhesive and mechanical mechanisms is proposed. Based on the basic bond-slip model, load-slip response, ultimate bond strength, and effective bond length of the HB-FRP bond interface are obtained by analytical or numerical solution. Good agreement between the analytical and experimental results indicates that the proposed bond-slip model can well predict bond behaviors of HB-FRP joints.

Experimental Study on Bond Characterization of Hybrid-Bonded FRP to Concrete Interfaces

2013 ◽  
Vol 790 ◽  
pp. 375-380 ◽  
Author(s):  
Kang Liu
Keyword(s):  
Experimental Study ◽  
Experimental Testing ◽  
Adhesive Bond ◽  
Interfacial Bond ◽  
Bond Lengths ◽  
Mechanical Fasteners ◽  
Single Shear

Pure adhesive bond of FRP to concrete is not only weak but also unreliable in a long term. This problem can be effectively overcome by a newly developed bond enhancement system the hybrid bonded FRP system (HB-FRP) in which small mechanical fasteners are used to augment the bond. In this paper, the bond behaviors of EB-FRP and HB-FRP joints were experimentally investigated by employing the single shear pull-off test on three EB-FRP and seven HB-FRP specimens with different bond lengths. Experimental testing is reported for characterization of the interfacial bond of the HB-FRP system.

scholarly journals Analytical Investigation on the Effect of Test Setup on Bond Strength

CivilEng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 14-34
Author(s):  
Konstantinos Tsiotsias ◽  
Stavroula J. Pantazopoulou
Keyword(s):  
Bond Strength ◽  
Pullout Test ◽  
Analytical Investigation ◽  
Strength Increase ◽  
Confining Stress ◽  
Direct Tension ◽  
Bond Slip ◽  
Test Setup ◽  
Long Time

Experimental procedures used for the study of reinforcement to concrete bond have been hampered for a long time by inconsistencies and large differences in the obtained behavior, such as bond strength and mode of failure, depending on the specimen form and setup used in the test. Bond is controlled by the mechanics of the interface between reinforcement and concrete, and is sensitive to the influences of extraneous factors, several of which underlie, but are not accounted for, in conventional pullout test setups. To understand and illustrate the importance of specimen form and testing arrangement, a series of computational simulations are used in the present work on eight distinct variants of conventional bar pullout test setups that are used routinely in experimental literature for the characterization of bond-slip laws. The resulting bond strength increase generated by unaccounted confining stress fields that arise around the bar because of the boundary conditions of the test setup is used to classify the tests with respect to their relevance with the intended use of the results. Of the pullout setups examined, the direct tension pullout test produced the most conservative bond strength results, completely eliminating the contributions from eccentricity and passive confinement.

Simfuel Leaching Studies in Granitic Groundwater Under Oxidizing Conditions

1995 ◽  
Vol 412 ◽  
Author(s):  
J. Garcia-Serrano ◽  
J. A. Serrano ◽  
P. P. Diaz-Arocas ◽  
J. Quiñones ◽  
J. L. R. Almazan
Keyword(s):  
Elemental Analysis ◽  
Particle Sizes ◽  
Leaching Tests ◽  
Minor Components ◽  
High Release ◽  
Synthetic Groundwater ◽  
Granitic Groundwater ◽  
Good Agreement

AbstractSimulated high-bumup nuclear fuel (SIMFUEL) has been leached in synthetic groundwater under oxic conditions. SIMFUEL pellets were ground and sieved to two particle sizes (50–100 and 100–315 μm). An extensive solid characterization of the fragments was carried out by various techniques. Elemental analysis has also been performed prior to the leaching tests.The release of U and the minor components (Mo, Ba and Sr) was monitored during the long term dissolution experiments (350 days). These minor components exhibit a trend similar to uranium, high release at the beginning followed by a plateau. The M/U calculated ratios show different behavior although after a period of time, depending on the particle sizes, constant ratios were observed.SIMHUEL powder was used in order to simulate the physical effect of bum-up on the fuel structure. This fact seems to play an important role on the uranium release. A comparison with the results given in the literature for SIMFUEL pellet leaching tests shows good agreement with the values reported.

Bond-Slip Mechanisms in Steel Micro-Fiber Reinforced Cement Composites

1994 ◽  
Vol 370 ◽  
Author(s):  
N. Banthia ◽  
N. Yan ◽  
C. Chan ◽  
C. Yan ◽  
A. Bentur
Keyword(s):  
Bond Strength ◽  
Silica Fume ◽  
Cement Composites ◽  
Interfacial Bond ◽  
Interfacial Bond Strength ◽  
Bond Slip ◽  
Pull Out ◽  
Fiber Size ◽  
The Matrix ◽  
Reinforced Cement

AbstractBond-slip characteristics for steel micro-fibers bonded in cement-based matrices were investigated by conducting single fiber pull-out tests. The influence of the following factors was investigated: fiber inclination, fiber size, fiber embedded length and matrix refinement using silica fume. It was found that the bond-slip characteristics of fibers aligned with respect to the loading direction were necessarily superior than those inclined at an angle. Inclined fibers supported smaller peak pull-out loads and absorbed lesser pull-out energies than the aligned fibers. The use of silica fume in the matrix was found to improve both the average interfacial bond strength and the maximum interfacial bond strength between the fiber and the matrix.

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 Active modulation of Hydrogen bonding by sericin enhances cryopreservation outcomes

2019 ◽  
Author(s):  
L. Underwood ◽  
J. Solocinski ◽  
E. Rosiek ◽  
Q. Osgood ◽  
N. Chakraborty
Keyword(s):  
Analytical Study ◽  
Molecular Level ◽  
Raman Microspectroscopy ◽  
Carcinoma Cells ◽  
Growth Potential ◽  
Scanning Calorimetry ◽  
Beneficial Effects ◽  
Aqueous Environments

AbstractCryopreservation of cells without any toxicity concerns is a critical step in ensuring successful clinical translation of cell-based technologies. Mitigating the toxicity concerns related to most of the commonly used cryoprotectants including dimethyl sulfoxide (DMSO) is an active area of research in cryobiology. In recent years use of additives including polymeric proteins such has sericin have been explored as an additive to cryoprotectant formulations. In this study the thermophysical effect of addition of sericin was investigated. The effect of presence of sericin on the H-bonding strength was investigated using Raman microspectroscopy and other thermophysical effects were quantified using differential scanning calorimetry (DSC) techniques. Finally, the prospect of using sericin as an additive to cryoprotectant formulation was investigated by monitoring cellular viability and growth following exposure to cryogenic temperatures in hepatocellular carcinoma cells. Results indicate significant improvement in post-thaw viability when sericin is used as an additive to DMSO based formulations. While use of trehalose as an additive has beneficial effects by itself, combined usage of sericin and trehalose as additives did result in an improved overall long-term growth potential of the cells.Statement of SignificanceThis study provides for powerful biophysical understanding of how sericin can be used as an additive for cryoprotectant solutions, which allows storage of biologics at low temperatures. It is desirable to replace current components of cryoprotectant formulation (such as DMSO) due to innate toxicity and metabolic derangements to cells. The ability of sericin to improve cryoprotective solutions was mechanistically characterized by Raman microspectroscopy, which allows for molecular level characterization of the nature of H-bonding in aqueous environments in presence of solution components. Thermodynamic analysis of the cryoprotectant solutions containing sericin was undertaken to quantify the relation between solution composition and cryopreservation outcome. This analytical study provides a basis for designing better cryoprotectants with lower thermophysical injury and higher cellular yields.

Characterization of Interfacial Bond Strength by Dynamic Analysis

1992 ◽  
Vol 26 (6) ◽  
pp. 869-882 ◽  
Author(s):  
J.M. Kennedy ◽  
D.D. Edie ◽  
A. Banerjee ◽  
R.J. Cano
Keyword(s):  
Bond Strength ◽  
Dynamic Analysis ◽  
Interfacial Bond ◽  
Interfacial Bond Strength

Mechanical and Chemical Characterization of a Metal-Bioceramic Interface

1989 ◽  
Vol 153 ◽  
Author(s):  
Mark J. Filiaggi ◽  
N. A. Coombs ◽  
R.M. Pilliar
Keyword(s):  
Fracture Toughness ◽  
High Resolution ◽  
Bond Strength ◽  
Chemical Characterization ◽  
Interfacial Fracture ◽  
Adhesive Bond ◽  
Interfacial Fracture Toughness ◽  
Implant Fixation ◽  
Resolution Electron

AbstractPlasma sprayed Hydroxyapatite (HA) coatings are applied to metal prostheses to allow for implant fixation through chemical bonding of the coating with surrounding bone tissue. Without a well-adhering coating, this fixation is threatened. Thus, a thorough characterization of the metal / ceramic interface is necessary. This study used a novel composite short bar interfacial fracture toughness technique with high resolution electron spectroscopic imaging to examine Ti-6AI-4V plasma spray coated with 100μm of HA. For this system, an interfacial fracture toughness value of 1.31 +/− 0.08 MPa·m1/2 was obtained, with a corresponding tensile adhesive bond strength of 6.7 +/− 1.5 MPa. High resolution ESI revealed distinct phosphorous segregation to the interface and diffusion into the underlying titanium. A 24-hour post-heat treatment at 960°C greatly increased the bond strength at this interface. Observations from ESI suggested that this effect may be due to enhanced diffusion of both phosphorous and calcium into the metal substrate.

Sign in / Sign up

Export Citation Format

Share Document