• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.333-336
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• 2004

In this study focuses on bond properties of hybrid FRP rebar after chemical environmental exposure. Hybrid FRP rebar bond specimens were subjected to four type of exposure conditions. Bond properties were investigated by direct bond test. Bond test results, hybrid FRP rebars were found to have better bond strength with concrete than currently using GFRP rebar. Also, hybrid FRP rebar had more than about $80\%$ in bond strength of steel rebar.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.445-448
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• 2004

Recently, bridge deck overlay with latex modified concrete is widely applied in domestic. the capacity of bridge deck overlay depends on bond state on the surface. factors that have an effect on bond state are clean condition on the surface, absence of surface microcracking, absence of laitance, overlay curing. In this study, it is researched that characteristic of bond strength according to moisture condition on the surface and the removal method of concrete. As a result, it shows high bond strength in dry condition when w/c is $31\%$ and in moisture condition when w/c is $38\%$ respectively. characteristic of bond strength according to the removal method of concrete shows high bond strength when using water-jets rather than jackhammers.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.201-207
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• 2002

An advanced fiber sheet has been widely used for strengthening of the concrete structures due to its excellent properties such as high strength and light weight. Bond strength is very important in strengthening the concrete structures using an advanced fiber sheet. This research examines the bond behavior between fiber sheet and concrete, investigates the bond strength by the direct pull-out test and the tensile-shear test. To obtain the tensile-shear strength a double-face shear type bond test is conducted. The primary test variables are the types of concrete surface roughness (disk-grinding/chipping) and retrofitting methods (bonding/injection). Thirty specimens were tested to evaluate the bond strength. It is shown that the average bond strength between fiber sheet and concrete by the direct pull-out test and the tensile-shear test is $22.3{\sim}23.1kgf/cm^2$ $17.92{\sim}19.75kgf/cm^2$, respectively.

• Advances in concrete construction
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• v.14 no.5
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• pp.331-339
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• 2022

Geopolymer concrete (GPC) is one of the best substitute materials for conventional concrete in construction. The conventional concrete provided by Portland cement has a detrimental influence on the environment during its production. In this study, the bond strength, which is an important structural property, of deformed steel bars with slag-based GPC was measured. In accordance with the ASTM C234 procedure, bond strength was measured on 18 specimens of slag-based GPC with three sizes of steel bars and different embedded lengths. Two groups of GPC specimens with different compressive strengths, which were cured under ambient conditions, were tested. The results indicated that the bar diameter has a great effect on the bond strength, and the bond strength behavior of the slag-based GPC is comparable with that of conventional concrete. The ACI-318 Code for the bond strength of ordinary Portland cement concrete can be used conservatively to determine the bond strength of the GPC reinforced with deformed steel bars.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.296-305
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• 2002

The main disadvantage of cement-retained implant restorations is their difficulty in retrievability. Advocates of cemented implant restorations frequently state that retrievability of the restoration can be maintained if a provisional cement is used. The purpose of this study was to find the optimal properties of provisional luting cements and the surface treatment of abutments in single implant abutment system. 30 prefabricated implant abutments, height 8mm, diameter 6mm, 3-degree taper per side, with light chamfer margins were obtained. Three commercially available provisional luting agents which were all zinc oxide eugenol type ; Cavitec, TempBond and TempBond NE were evaluated. No cement served as the control. TempBond along with vaseline, a kind of petrolatum (2:1 ratio) was also evaluated. Ten out of thirty abutments were randomly selected and abutment surfaces were sandblasted with $50{\mu}m$ aluminum oxide. Another ten abutments were sandblasted with $250{\mu}m$ aluminum oxide. A vertical groove, 1 mm deep and 5mm long was cut in each twenty abutments. Ten of them were sandblasted with $50{\mu}m$ aluminum oxide. The full coverage casting crowns were cemented to the abutments with the designated provisional luting agent. Specimens were stored in distilled water at $37^{\circ}C$ for 24 hours. Each specimen was attached to a universal testing machine. A crosshead speed of 0.5mm/min was used to apply a tensile force to each specimen. Within the limitations of this in vitro study, the following conclusions were drawn: 1. Tensile bond strength of provisional luting cements in no surface treatment decreased with the sequence of TempBond NE, TempBond, Cavitec, TempBond with vaseline, no cement. 2. Tensile bond strength more increased by surface treatment. Sandblasting with $250{\mu}m$ aluminum oxide exhibited the highest tensile bond strength in the abutment cemented with TempBond NE and sandblasting with $50{\mu}m$ aluminum oxide exhibited the highest tensile bond strength in cemented with TempBond. 3. In the aspect of a groove formation, tensile bond strength significantly increased in TempBond with vaseline only and the others had no significant effect on tensile bond strength.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.126-142
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• 1991

The purpose of this study was to evaluate the effect of various dentin surface treatments on shear bond strength, microhardness and fracture mode before and after thermocycling. Recently extracted 75 human molars were used. The teeth were sagittal sectioned faciolingually to obtain 150 specimens. They were randomly divided into six groups. Mesial and distal dentinal surfaces of specimens were exposed by grinding and treated respectively with GC-DENTIN CONDITIONER. 10-3 solution of 4-Meta, Cleansar and Primer of GLUMA, Scotchprep of Scotchbond 2, DENTIN CONDITIONER and PRIMER A, B of ALL BOND according to the manufacturers directions. Specimens of one group were not treated. Adhesive agent of Scotchbond 2, were applied and cured on the treated dentin surfaces. After P-50 were cured on them, specimens were stored in 31c water for 24 hours before shear bond strength measurement Shear bond strength was measured in 10 specimens of each group. 10 specimens of each group were thermocycled in $20^{\circ}C$, $60^{\circ}C$,$20^{\circ}C$, $4^{\circ}C$, $20^{\circ}C$ water in order, for 30 seconds respectively, 100 times a day for 7 days. After thermocycling shear bond strength was measured. Microhardness was checked on treated dentin surface and fractured dentin surface in 10 specimens respectievly. Francture modes were observed with SEM The following results were obtained. 1. Before thermocycling. shear bond strengths in the specimens treated with DENTIN CONDITIONER and PRIMER A, B of ALL BOND were significantly higher than those in other specimens(P<0.01). 2. After thermocycling. shear bond strengths in the specimens treated with Cleanser and Primer of GLUMA, Scotchprep of Scotchbond 2 and DENTIN CONDITIONER and PRIMER A, B of AIL BOND were significantly higher than those in specimens not: treated, treated with GC-DENTIN CONDITIONER and 10-3 solution of 4-Meta(P<0.01). Shear bond strengths in the specimens treated with GC-DENTIN CONDITIONER and PRIMER A, B of ALL BOND were significantly higher than those in other specimens except those treated with Scotchprep of Srotchbond 2(P<0.01). 3. Shear bond strengths after thermocycling were reduced in the specimens not treated, treated with GC-DENTIN CONDITIONER and 10-3 solution of 4-Meta and were increased in the specimens treated with Cleanser and Primer of GLUMA, Scotchprep of Scotchbond 2, without significance, compared with those before thermocycling. In the specimens treated with DENTIN CONDITIONER and PRIMER A, B of ALL BOND, shear bond strengths after thermocycling were significantly increased, compared with those before thermocycling(P<0.01). 4. Microhardnesses in the fractured surfaces after shear bond strength measurement were significantly increased in the specimens treated with 10-3 solution of 4-Meta and significantly decreased in the specimens treated with DENTIN CONDITIONER and PRIMER A, B of ALL BOND, compared with those in the treated dentin surfaces(P<0.01). 5. In the specimens treated with Cleanser and Primer of GLUMA, Scotchprep of Scotchbond 2 and DENTIN CONDITIONER and PRIMER A, B of ALL BOND, cohesive fracture modes were observed more than adhesive fracture modes.

• The korean journal of orthodontics
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• v.40 no.4
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• pp.267-275
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• 2010

Objective: The aim of this study was to evaluate and compare the shear bond strength (SBS) and failure-mode of orthodontic buttons bonded to erupted and unerupted teeth with conventional and self-etching adhesive systems. Methods: Eighty-four erupted and 84 unerupted, human third-molar teeth were used. For both groups, the buccal surfaces of each tooth were assigned one of the following type of adhesive systems (n = 12). A, Conventional systems: 1, Transbond XT (3M Unitek, Monrovia, CA, USA); 2, Prime & Bond NT (Dentsply/Caulk, Milford, USA); 3, Single Bond (3M ESPE, Minnesota, USA); and B, Self-etching adhesives; 4, Clearfil SE Bond (Kuraray, Okayama, Japan); 5, Transbond Plus (3M Unitek, Monrovia, CA, USA); 6, Clearfil S3 (Kuraray, Tokyo, Japan); 7, G Bond (GC, Tokyo, Japan). The SBSs of the attachments and the adhesive remnant index (ARI) scores were recorded. Data were analyzed with analysis of variance (ANOVA), independent-sample t-test and chi-square tests. Results: When the SBSs of erupted and unerupted teeth were compared, only the Clearfil-SE Bond and G-Bond were significantly different. Bond strengths of all adhesive systems were higher in unerupted teeth than erupted teeth, except the Single-Bond system. Conclusions: When using conventional adhesives, bonding to erupted and unerupted teeth may not be significantly different. However, clinicians need to take into consideration the types of self-etching systems before usage.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.285-291
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• 2007

The purpose of this study was to evaluate the effect of collagenase and esterase on the microtensile bond $strength({\mu}TBS)$ in dentin bonding. After resin composites were bonded to occlusal dentin. ${\mu}TBS$ specimens were formed and stored in PBS, collagenase, or esterase solution After 4-week storage, ${\mu}TBS$ was determined and, the results were as follows : 1. ${\mu}TBS$ values of Single Bond 2 were lower than those of Clearfil SE Bond for all storage medium (p<0.05). 2. In Single Bond 2 group, collagenase solution lowered bond strength more than PBS and esterase solution (p>0.05). 3. In Clearfil SE Bond group, esterase solution lowered bond strength more than PBS(p>0.05). Collagenase solution lowered bond strength more than esterase solution(p>0.05) and PBS(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.436-444
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• 2018

The purpose of this study was to compare the shear bond strengths of 3-in-1 flowable composite to the enamel and dentin of primary teeth to previous adhesive systems. 110 primary incisors were prepared and divided into two groups: Dentin group included 5 groups: 1) Scotch bond Multi-purpose plus(DSM), 2) Single-bond 2(DSB), 3) Clearfil SE bond(DSE), 4) All bond universal(DAB), 5) Constic(DC), and Enamel group included 6 groups: 1) Scotch bond Multi-purpose plus(ESM), 2) Single bond 2(ESB), 3) Clearfil SE bond(ESE), 4) All bond universal(EAB), 5) Constic(EC), 6) Constic with additional etching(ECE). A cylinder of composite was bonded to the prepared surface, and the shear bond strength was measured. In the dentin groups, group DC had significantly lower shear bond strength than group DSE. No significant difference was found between group DC, group DSM, group DSB and group DAB. In the enamel groups, there was no significant difference between group EC, group ESE, and group EAB. This material showed lowest shear bond strength among all tested materials in both enamel and dentin groups, showing insignificant difference with some adhesive systems. Therefore, 3-in-1 flowable composite can be used for primary teeth restoration but further studies are needed.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.169-178
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• 1998

Bond strength of reinforcing bar to high-perfomance concrete using belite cement is explored using beam end test specimens. The key parameters for the bond test are slump of concrete, top bar effect, and strength of concrete in addition to concrete cover. The test results show that the specimens with belite cement concrete show approximately 10% higer bond strength than those with portland cement concrete. The results also show that the bond strength from the high strength concrete is function of the square root of concrete compressive strength. Bond strength of the top bar is less than bond strength of bottom bar, but the ratios of the bond strength of bottom-cast bars to those for top-cast bars are much less than the modification factor for top reinforcement found in the ACI 318-95 code. Comparisons with other reported tests identified that belite cement increased bond strength while silica fume or flyash used in high strength concrete decreased bond strength. The high-strength and high-slump concrete with belite cement performs well in terms of bond strength to reinforcing steel.