• International Journal of Highway Engineering
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• v.16 no.5
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• pp.1-8
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• 2014

PURPOSES : The objective of this study is to evaluate the bond strength of asphalt emulsions including polymer-modified emulsions for chip seals and fog seals using the bitumen bond strength (BBS) test. METHODS : For the laboratory testing, the Pneumatic Adhesion tensile Testing Instrument(PATTI) device is used to measure the bond strength between the asphalt emulsion and aggregate substrate based on the AASHTO TP-91. In order to conduct all the tests in controled condition, all test procedures are performed in the environmental chamber. The CRS-2L and the SBS CRS-2P emulsions are used as a polymer-modified emulsion, and then unmodified emulsion, the CRS-2, is compared for the evaluation of chip seal performance. For the fog seal performance evaluation, two types of polymer-modified emulsions and one of unmodified emulsion, the CSS-1H, are employed. For chip seal study, the BBS tests are performed at 30, 60, 120, and 240 minutes of curing times with curing and testing temperatures of $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$. The fog seal tests are conducted at 30, 60, 90, 120, 180 minutes, and 24 hours with curing and testing temperatures of $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$. RESULTS AND CONCLUSIONS : Overall, chip seal emulsions and fog seal emulsions show the similar bond strength trend. At the same testing condition, polymer-modified emulsions show better bond strength than unmodified emulsions. Also, there is no significant difference between polymer-modified emulsions. One of important findings is that the most bond strength reaches their final bond strength within one hour of curing time. Therefore, the early curing time plays a vital role in the performance of chip seals and fog seals.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4A
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• pp.279-286
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• 2011

FRP (Fiber Reinforced Polymer) tendons can be used as an alternative to solve the corrosion problem of steel tendons. Material properties of FRP tendons-bond strength, transfer length, development length-must be determined in order to apply to concrete structures. First of all, in case of application for pretension concrete members with CFRP tendons, transfer length is an important characteristic. The bond of the material characteristics should be demanded clearly to apply to PSC structures prestressed with FRP tendons. This paper investigated on the bond characteristics of FRP reinforcements with various surface-type. To determine the bond characteristics of FRP materials used in place of steel reinforcement or prestressing tendon in concrete, pull-out testing suggested by CAN/CSA S806-02 was performed. A total of 40 specimens were made of concrete cube with steel strands, deformed steel bar and 6 different surface shape FRP materials like carbon or E-glass. Results of the bonding tests presented that each specimen showed various behaviors as the bond stress-slip curve and compared with the bond characteristic of CFRP tendon developed in Korea.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.450-460
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• 1996

The purpose of this study was to compare shear bond strength of composite resin using several dentin bonding agents and light cured glass ionomer cement(Fuji II LC). 40 Bovine primary anterior teeth were used for this experiment. Labial surface of teeth were flattened. It were divided into four groups. Each group was composed of 10 teeth. The material used for this experiment were Scotchbond Multipurpose-Z-100, Allbond 2-Aelitefil, Gluma-Pekalux, light cured glass ionomer cement(Fuji II LC). Each of the materials was applied to the exposed surfaces of 10 teeth by insertion into a cylindrical shaped matrix which is 3mm diameter and 3mm in height. The completed specimens were stored at $37^{\circ}C$ under 100% humidity for 24 hours : the shear bond strength of each material to dentin surface were measured with INSTRON universal testing machine. The results were as follows : 1. Shear bond strength to dentin surface increased in order of light cured glass ionomer cement(Fuji II LC), Gluma, Allbond 2, Scotchbond Multipurpose. 2. Between shear bond strength of light cured glass ionomer cement(Fuji II LC) and Allbond 2, there was statistical significace(p<0.05) 3. Between shear bond strength of light cured glass ionomer cement(Fuji II LC) and Scotchbond Multipurpose, between shear bond strength of Gluma and Scotchbond Multipurpose, there was statistical significance.(p<0.01) The shear bond strength of dentin bonding agents were higher than light cured glass ionomer cement. The reason is that materials and quality of dentin bonding agent were enhanced. Further investigation is necessary to improve shear bond strength of light cured glass ionomer cement.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.180-192
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• 2000

One bottle system was recently developed in order to simplify the clinical skills and save chair time after continuous improvements on dentin bonding agents. There has been many studies to measure the bond strength of one bottle systems but no actual work has been done on micromorphologic study of resin-dentin interdiffusion zone after one bottle system application. To evaluate the bonding patterns of various commercially available one bottle systems to dentin, observation of resin-dentin interdiffusion zone under TEM was performed. Caries-free human third molars within one month of extractions were chosen for the experiments. The molars were sectioned 1mm above the cementoenamel junction and got rid of the root portions. Crown portions of the teeth were sectioned parallel to occlusal surface so that dentin discs of 1mm in thickness were remained. 7 one bottle systems and 1 two bottle system were applied according to manufacturer's instructions and followings were the results. 1. In every experimental groups, cross bandings of collagen fiber were distinguishable and tight bon dings between the bonding agents and dentin were observed. 2. Hybrid layer was clearly observed in ONE-STEP$^{(R)}$, Prime & Bond$^{(R)}$ 2.1, Syntac$^{(R)}$ SC, MAC-BOND II groups but it was not clear in Single Bond, D-Liner Dual PLUS, ONE COAT BOND groups. 3. Electron-density of hybrid layer was uniform in pattern in MAC-BOND II, Prime & Bond$^{(R)}$ 2.1 groups but not so uniform in ONE-STEP$^{(R)}$ group. 4. Electron-dense amorphous phase in most superior layer of the resin-dentin interdiffusion zone was characteristically observed in Single Bond, Syntac$^{(R)}$ SC, ONE COAT BOND groups. It can be concluded that bondings between the dentin bonding agents and dentin can be various in pattern according to their chemical compositions and the condition during applications.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.1
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• pp.55-64
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• 1992

This study investigated the effect of porcelain primer on bonding of coomposite resin to porcelain surface. In order to test the bond strength between porcelain and composite resin, porcelain cylinders were embedded in acrylic resin, and polished with 240grit silicone caqrbide paper. The specimens were divided into twelve groups. All specimens were treated with three porcelain primers and bonded with five composite resins. All test groups were stored in $37^{\circ}C$ distilled water for 48hours. Shear bond strengths were measured with Instron(Model 4201) at a cross-head speed of 1mm/min. The obtained results were as follows : 1. Scotchprime/Silux II group and BISCO Porcelain Primer/Bisfill group showed significant higher bond strengths than Clearfil Porcelain Primer/photo Clearfil Bright group(p<0.05). And there was no significant differences in bond strengths between Scotchprime/Silux II group and BISCO Porcelain Primer/Bisfill group(p>0.05). 2. When composite resins were used with Scotchprime, the bond strengths were decresed Silux II$(16.68{\pm}3.35MPa)$, Bisfil$(16.23{\pm}4.54MPa)$, Poly-Fill$(14.74{\pm}4.08MPa)$, Photo Clearfil Bright$(13.75{\pm}2.89MPa)$ and Pekalux$(14.74{\pm}4.08MPa)$ in order, but there was no statistical significance(p>0.05). 3. When composite resins were used with BISCO Porcelain Primer, the bond strength were decreased Bisfil$(16.17{\pm}1.60MPa)$, Silux II$(12.13{\pm}2.37MPa)$, Poly-Fill$(10.78{\pm}1.99MPa)$, Photo Cleafil Bright $(9.91{\pm}4.59MPa)$ and Pekalux$(7.36{\pm}2.16MPa)$ in order, but there was no statistical significance(p>0.05). 4. Silux II, Photo Clearfil Bright and Poly-Fill used with Scotchprime showed significant higher bond strengths than BISCO Porcelain Primer(p>0.05).

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.600-604
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• 1989

In order to find the rational methods for improving the thermal stability of subtilisin Carlsberg, the mechanisms of irreversible thermoinactivation of the enzyme were studied at $90^{\circ}C.$ At pH 4, the main process was hydrolysis of peptide bond. This process followed first order kinetics, yielding a rate constant of $1.26\;{\times}\;10^{-1}h^{-1}$. Hydrolysis of peptide bond of PMS-subtilisin occurred at various sites, which produced new distinct fragments of molecular weights of 27.2 KD, 25.9 KD, 25.0 KD, 22.3 KD, 19.0 KD, 17.6 KD, 16.5 KD, 15.7 KD, 15.0 KD, 13.7 KD, and 12.7 KD. Most of the new fragments originated from the acidic hydrolysis at the C-side of aspartic acid residues. However 25.0 KD, 15.7 KD, and 13.7 KD which could not be removed in purification steps stemmed from the autolytic cleavage of subtilisin. The minor process at pH 4 was deamidation at asparagine and/or glutamine residues and some extend of aggregation was also observed. However, the aggregation was main process at pH 7 with a first order kinetic constant of $16 h^{-1}.$ At pH 9, the main process seemed to be combination of deamidation and cleavage of peptide bond.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.195-198
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• 2008

Graphite and $MoS_2$ were added respectively to the Cu/Sn bond materials of the same composition as a lubricant in order to find out the effect of lubricants on the mechanical properties and the increase in density of the sintered products for microblades. The addition of $MoS_2$ as a lubricant was more beneficial to strength, fracture toughness, and hardness as well as densification than graphite. $MoS_2$ seemed to be more effective in reducing the friction between the metallic powders and die wall during hot pressing process. Due to the better wettability of MoS2 with bond metal alloy, less amount of interfacial defects which is detrimental to mechanical properties use observed.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.189-192
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• 2005

Glass fiber reinforced polymer (GFRP) bars gain increasingly more attention as a reinforcing option for concrete because of their corrosion resistance and non-magnetism. GFRP reinforcement for concrete does not have the same shape as steel reinforcement. Therefore, the bond performance of FRP bars, unlike that of steel, is dependent on their design, manufacture and mechanical properties. This paper studied the effect of high strength concrete on the bond strength of GFRP bars. Twenty-nine specimens having different compressive strength of concrete were tested in order to examine the bond behavior of GFRP bars.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.290-293
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• 2006

Glass fiber reinforced polymer (GFRP) bars gain increasingly more attention in the civil engineering community. GFRP reinforcement for concrete does not have the same shape as steel reinforcement. Therefore, the bond performance of FRP bars, unlike that of steel, is dependent on their design, manufacture and mechanical properties. It was tested in order to examine the bond behavior of GFRP bars under different compressive strength of concrete. Test results showed that the bond strength of GFRP increased with the compressive strength of concrete.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.2
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• pp.200-213
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• 1991

ln order to acquire the fundamental data for the organic solvents in bond and to contribute the health improvement of workers in deprtment of organic solvents in shoes manufacturing industries. The authors surveyed the contents of organic solvent in adhesive and determined the amount of volatilization of organic solvent by time and temperature with gaschromatography from March to September 1990. The results were as follows; 1) The kinds for organic solvents in bond were 9 that was Toluene, C-Hexane, N-Hexane, C-Hexanon, Aceton, Methyl Ethyl Keton, Dimethyl Formamide, Etyly Acetate. 2) Toluene and Methyl Ethyl Keton among the organic solvents in adhesive were over 80.18%. 3) The amount of volatilization of Methyl Cyclohexanone and Aceton by time and temperature were the most level than other compounds.