• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.70-75
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• 2001

There is a problem to be solved for improvement of durability and safety for concrete When the waterproofing and anticorrosive work of main concrete are design, the material a of construction need to be correctly applied to appropriate circumstance conditions. Epoxy mostly been used for concrete water tank structure. Lately, lots of subjects on adaption res in mortar for waterproofing and anticorrosive are under discussion. Then, we attempt to approach by evaluating and comparing every capabilities with waterproofing materials in this experiment. Capability evaluation items include the bond age and curing conditions, the bond strength after accelerated weathering test and fret impact resistance, a mount of water, seepage quan Through the experiment analysis, we found that waterproofingtity, drinking water chemicals resistance. and anticorrosive resin mortar used with glass fiber cloth, inorgar material is dominantly superior to other waterproofing materials. According to this paper, we suggest the resin mortar as a new surface treatment material water tank structure.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.650-658
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• 2000

This study was investigated to compare the bond strength of polysulfide adhesive between tray resin and border molding materials and to evaluate the effect of saliva contamination on them. We made the 135 resin tray secimens with a dimension of $1{\times}1{\times}1cm$ and divided them into 3 groups by the materials 1) Quicky group, 2) Compound group, and 3) Impregum group Each group was subdivided by saliva contimination. Group S1 : applied adhesive without saliva contamination Group S2 : applied adhesive after drying 15seconds after saliva contamination Group S3 : applied adhesive no after saliva contamination. Tensile tests were performed with a Universal Load testing machine. Results showed Impregum group significantly higher bond strength than Quicky group, but there was no significant difference in adhesive bond strength between Compound group and Quicky group in experimental group by materials In experimental group by saliva contamination, S1 group is significantly higher bond strength than S2 group and S2 group is significantly higher bond strength than S3 group in Quicky group and S1, S2 group is significantly higher bond strength than S3 group in Compound group and Impregum group. Impression compound and Impregum F which are usually used as an individual tray border mold-ing material can be said to be satisfied in adhesive bond strength to polysulfide impression materials. After try-in and clinical adjustment are performed, a custom tray should be properly rinsed and air dried before tray adhesive was placed.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.18.1-18.12
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• 2018

Objectives: This study compared the retention of BioAggregate (BA; Innovative BioCeramix) and mineral trioxide aggregate (MTA; Angelus) as coronal plugs after applying different intracanal medications (ICMs) used in regenerative endodontic. Materials and Methods: One-hundred human maxillary central incisors were used. The canals were enlarged to a diameter of 1.7 mm. Specimens were divided into 5 groups (n = 20) according to the ICM used: calcium hydroxide (CH), 2% chlorhexidine (CHX), triple-antibiotic paste (TAP), double-antibiotic paste (DAP), and no ICM (control; CON). After 3 weeks of application, ICMs were removed and BA or MTA were placed as the plug material (n = 10). The push-out bond strength and the mode of failure were assessed. The data were analyzed using 2-way analysis of variance, the Tukey's test, and the ${\chi}^2$ test; p values < 0.05 indicated statistical significance. Results: The type of ICM and the type of plug material significantly affected bond strength (p < 0.01). Regardless of the type of ICM, BA showed a lower bond strength than MTA (p < 0.05). For MTA, CH showed a higher bond strength than CON, TAP and DAP; CHX showed a higher bond strength than DAP (p < 0.01). For BA, CH showed a higher bond strength than DAP (p < 0.05). The mode of failure was predominantly cohesive for BA (p < 0.05). Conclusions: MTA may show better retention than BA. The mode of bond failure with BA can be predominantly cohesive. BA retention may be less affected by ICM type than MTA retention.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.493-502
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• 2003

Statement of problem : Removable partial denture and complete denture often require denture base relines to improve the fittness against tissue-bearing mucosa because of the gradual change in edentulous ridge contour and resorption of underlyng bony structure. Self-curing hard reline resins offers the immediate and relatively inexpensive means to be recondition the surface of denture base directly However weak bond between denture base resin and reline material can harbor bacteria, promote staining, or result in complete separation of the two materials. Purpose : The purpose of this study was to evaluate the effect of denture cleansers on bond strength and surface hardness of reline resin to denture base resin Denture base resin beams($60.0{\times}15.0{\times}3.0mm$) were made with Lucitone 199. Material and methods : 10mm section was removed from the center of each specimen. The samples were replaced in the molds and the space of l0mm sections were packed with Tokuso Rebase reline material. The specimens were immersed in denture cleansers (Polident, Cleadent) and were evaluated after 1 week, 2 weeks, and 4 weeks. The bond strength and surface hardness of self-curing hard reline materials to heat-curing denture base resin were measured using an UTM (universal testing machine). Results and conclusion : 1) There was no significant difference of usage, kind, and denture cleaner by application time on the bonding strength of self-curing hard reline resin to denture base resin. 2) There was no significant difference of usage, kind, and denture cleaner by application time on the surface hardness, but the surface hardness showed decreasing tendency, as the time of immersion was extended. 3) The failure modes of the specimens was initially adhesive failure and finally cohesive failure of self-curing hard reline resin.

• The Journal of Advanced Prosthodontics
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• v.11 no.2
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• pp.95-104
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• 2019

PURPOSE. To evaluate the effect of surface treatments and repair materials on the shear bond strength and to measure the fracture toughness of CAD/CAM provisional restoration materials. MATERIALS AND METHODS. Four CAD/CAM (3D printing: Nextdent C&B and ZMD-1000B Temporary, CAD/CAM resin block: Yamahachi PMMA disk and Huge PMMA block) and four conventional (monometacrylate: Jet and Alike, dimetacrylate: Luxatemp and Protemp 4) materials were selected to fabricate disk-shaped specimens and divided into six groups according to surface treatment (n=10). CAD/CAM materials were repaired with Jet or Luxatemp, while conventional materials were repaired with their own materials. The shear bond strength was measured by using universal testing machine. Ten rectangular column-shaped specimens for each material were fabricated to measure the fracture toughness by single edge v notched beam technique. Statistical analysis was performed by one-way ANOVA. RESULTS. The highest shear bond strength of CAD/CAM materials was achieved by SiC paper + sandblasting. It was also accomplished when repairing 3D printing materials with Luxatemp, and repairing CAD/CAM resin blocks with Jet. Yamahachi PMMA disk showed the highest fracture toughness. Nextdent C&B showed the lowest fracture toughness value but no statistically significant difference from Alike and Luxatemp (P>.05). CONCLUSION. In order to successfully repair the CAD/CAM provisional restoration, mechanical surface treatment and appropriate repair material according to the CAD/CAM material type should be selected. The CAD/CAM provisional materials have proper mechanical properties for clinical use as compared to conventional materials.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.1-9
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• 2016

PURPOSES : This study focuses on the evaluation of interface performance with varying surface texture and tack coat application in an asphalt overlay. METHODS : The evaluation is carried out in two phases: tracking test and interface bond strength test. Using an image processing tool, tracking test is conducted to evaluate the susceptibility of the tack coat material to produce excessive tracking during application. Using the pull-off test method, the bond strength test is performed to determine the ability of the interface layer to resist failure. RESULTS : Results show that the underseal application yields less tracking compared to other applications. However, the bond strength is barely within the minimum acceptable value. On the other hand, RSC-4 produces higher bond strength for all surface types, but the drying time is long, which produces excessive tracking. CONCLUSIONS : While underseal application may be suitable for a trackless condition, the bond strength is less appealing compared to the rest of the tack applications available. RSC-4 demonstrated a high and consistent bond strength performance, but more time is required for drying to avoid excessive tracking. Tack coat application and surface type combination produce varying results. Therefore, these should be considered when selecting suitable future tack coat application options.

• Journal of the Korean Ceramic Society
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• v.43 no.7 s.290
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• pp.415-420
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• 2006

The residual stresses in the interface region of the Thermal Barrier Coating (TBC)/Thermally Grown Oxide (TGO)/Bond Coat (BC) were calculated on the TBC-coated superalloy samples using a Finite Element Method (FEM). It was found that the stress distribution of the interface boundary was dependent upon mainly the geometrical shape or its aspect ratio and the thickness of TGO layer, which was formed by growth and swelling behavior of oxide layer. Maximum compressive residual stress in the TBC/TGO interface is higher than that of the TGO/bond coat interface, and the tensile stress had nothing to do with change of an aspect ratio. The compressive residual stresses in the TBC/TGO and TGO/bond coat interface region increased gradually with the TGO growth.

• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.988-994
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• 1998

In the manufacturing of vitreous bonded CBN tool the porosity change associated with various processing conditions, I. e. the sintering temperature and the size and the amount of abrasive grits was observed. In the case of sintering of vitreous bond material only the specimen density reached the maximum at 950$^{\circ}C$ and then the total porosity was increased slightly with the temperature above 950$^{\circ}C$. In the sintering of a-brasive grits and the vitreous bond material together a marked increase in the total porosity was found with the temperature above 950$^{\circ}C$ Reducing the grit size at the constant volume fraction of abrasive grits showed an increase in the total porosity at whole sintering temperature. On the contrary. it was observed that increasing the volume fraction of abrasive grits with a same size showed the increased open porosity simultaneously with decreased closed porosity at whole sintering temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.65-68
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• 1991

Finite element analysis is used to study the role of interfacial properties on the bond strength of reinforcing steel to concrete. Specifically, the role played by epoxy coatings on the failure of standard beam-end specimens is explored. Experimental results show that epoxy coatings reduce bond strength, but that the effect is dependent on the bar size and the deformation pattern. The finite element model for the beam-end specimen includes representations for the deformed steel bar, the concrete, and the interfacial material. The interface elements can be varied to match the stiffness and friction properties of the interfacial material. Cracking within the concrete is represented using Hillerborg's ficticious crack model. The model is used to study important aspects or behavior observed in the tests and to provide an explanation for the effect of the various test parameters.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.787-792
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• 2000

Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel. For various conditions of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and the material removal are measured and discussed. The results are as follows.