• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.721-730
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• 2012

The present paper presents a numerical study on multiphase flows induced by wall adhesion. The continuum surface force (CSF) model with the wall adhesion boundary condition model is used for calculating the surface tension force; this model is implemented in an in-house solution code (PowerCFD). The present method (code) employs an unstructured cell-centered method based on a conservative pressure-based finite-volume method with a volume capturing method (CICSAM) in a volume of fluid (VOF) scheme for phase interface capturing. The effects of wall adhesion are then numerically simulated by using the present method for a shallow pool of water located at the bottom of a cylindrical tank with no external forces such as gravity. Two different cases are computed, one in which the water wets the wall and one in which the water does not wet the wall. It is found that the present method efficiently simulates the surface tension-dominant multiphase flows induced by wall adhesion.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.343-348
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• 2000

The purpose of this study is to clarify properties adhesive strength of polymer-cement slurry for coated reinforcing bars. The epoxy coating material is superior to performance of anti-corrosion but lately age adhesive strength between concrete raise to structural problems. However, polymer dispersion with excellent performance of elasticity and adhesion can solve this problems. From the test results. adhesion of steel with polymer cement slurry using St/BA emulsion is show excellent without concerned coating thickness, and polymer cement slurry using St/BA emulsion is show adhesion in tension 1.2~2.2MPa at polymer cement ratio 50% of more.

• Journal of Adhesion and Interface
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• v.2 no.3
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• pp.9-15
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• 2001

To estimate the effect of the surface state of the EVA foam on an adhesion, the surface was treated with solvents having different values of a solubility parameter and a surface tension. The morphology and the contact angle were measured by SEM and contact angle tester, respectively. The value of the critical surface tension(${\gamma}_{c,0}$) of the EVA foam calculated by Zismann plot was 27.08 dyne/cm. The surface state and the ${\gamma}_c$ of the EVA foam were changed by solvent treatment. The swelling ratio of EVA foam was influenced by solubility parameter of a solvent, on the other hand the degree of change in the surface state was dependent on a surface tension of a solvent. When a surface tension of solvent. When a surface tension of solvent is lower than ${\gamma}_{c,0}$ of the EVA foam, the wettability of a solvent was good and the surface state was greatly changed. The adhesion strength of EVA foam was greatly improved to above 600% as compared to that of the untreated one. As the ${\gamma}_c$ of EVA was closed to the surface tension of the primer, the good adhesion strength was obtained.

• KCI Concrete Journal
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• v.13 no.2
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• pp.58-66
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• 2001

Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top coat with thin thickness, typically 5~15mm. The purpose of this study is to evaluate basic properties of self-leveling materials using polymer dispersions as kinds of SBR, PAE, St/BA with thin coat (under 3mm). Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as to facilitate the workability required. The self-leveling materials using four types of polymer dispersion are prepared with polymer-cement ratio which respectively range from 50% and 75%, and tested for basic characteristics such as unit weight, air content, flow, consistency change and adhesion in tension. From the test results, the self-leveling materials using PAE emulsion at curing age of 28days are almost equal to those of conventional floor using urethane and epoxy resin. The adhesion in tension of self-leveling mortars using SBR latex and PAE emulsion at curing age of 3days is over 17 kgf/cm$^2$(1.67MPa). Consistency change is strongly dependent on the type of polymer dispersion. It is concluded that the self-leveling materials using polymer dispersions can be used in the same manner as conventional floor using thermosetting resin in practical applications, in the selection of polymer dispersions.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.23-34
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• 2022

The purpose of this study is to evaluate the adhesion properties of polymer cement composites for crack repair of an RC structure. Polymer cement composites are manufactured from cement, three types of polymers and silica fume, and the mixture is designed by adjusting the water cement ratio and AE reducing agent so that the viscosity target of the polymer cement composites is 700mPa·s or less. According to the test results, the Type-A adhesion in tension of the polymer cement composite exceeded the adhesion standard of 1.0MPa of the polymer finishing material, and furthermore, depending on the type of polymer, the adhesion in tension was highest for SAE, followed in descending order by EVA, and SBR. In addition, the adhesion in tension of Type-B is up to 1/4.5 lower than that of Type-A, but the incorporation of silica fume shows a significant improvement in terms of adhesion in tension. Based on this study, the basic mixing design of the polymer cement composites required for viscosity and adhesive performance required for crack repair of the RC structure was completed. It could be proposed as an optimal mixing design under conditions for intermixing polymer type EVA, SAE, and P/C 80%-100%.

• Geomechanics and Engineering
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• v.4 no.3
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• pp.209-218
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• 2012

This paper presents the derivation of an analytical expression for the dynamic active thrust from c-${\phi}$ (c = cohesion, ${\phi}$ = angle of shearing resistance) soil backfill on rigid retaining walls with wall friction and adhesion. The derivation uses the pseudo-static approach considering tension cracks in the backfill, a uniform surcharge on the backfill, and horizontal and vertical seismic loadings. The development of an explicit analytical expression for the critical inclination of the failure plane within the soil backfill is described. It is shown that the analytical expression gives the same results for simpler special cases previously reported in the literature.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.2
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• pp.109-115
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• 2008

A Plastic Bonded Explosive(PBX) is mainly composed of nitramine explosive and polymer binder. The great number of serious applications of PBX requires the good adhesion between nitramine crystals and binder, which depends on the surface characteristics of a filler and binder. In the pursuit of the better design to achieve the enhanced adhesion, profound knowledge of the surface and interfacial characteristics of explosive and binder should be exploited. In this study, the influences of physicochemical properties between RDX and binders such as interfacial tension($\gamma_{SL}$), latent heat($Q_m$), and density($\rho$) on impact sensitivity of PBX were investigated. As experimental results, the major contribution factor to impact sensitivity of PBX was the interfacial tension, compare with other surface properties. The correlation coefficient of $H_{50}$ versus $\gamma_{SL}$ is 0.9932 when a polynomial regression method was used.

• Journal of Adhesion and Interface
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• v.24 no.2
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• pp.54-59
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• 2023

Silver nanowire-based transparent electrodes are very attractive as a next-generation flexible and transparent electrode that can replace ITO-based flexible electrodes because they have excellent conductivity, transmittance and mechanical flexibility. However, weak understanding of the silver nanowire solution for the fabrication of silver nanowire-based transparent electrodes often cause abnormal operation of the electrical device or peeling problem of the electrode films when applied to electronic devices. Here, we studied a Hydroxypropyl Methylcellulose (HPMC) adhesion promoter, which is one of the additives for silver nanowire solution, to improve the understanding of silver nanowire solution. In detail, it is characterized how the HPMC changes the properties of silver nanowire solution and silver nanowire film, which is fabricated with silver nanowire solution including the HPMC adhesion promoter. As the characteristics of solution, polar surface tension and dispersive surface tension were measured. As the film characteristics, surface energy, surface morphology, silver nanowire density, and sheet resistance were analyzed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.179-180
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• 2023

The adhesion performance of PCCs for crack repair of RC structures was greater in the case of using ultra high-early strength cement than in the case of using ordinary Portland cement, and the effect of mixing silica fume was higher in the case of ordinary Portland cement than that of ultra high-early strength cement. On the other hand, 130% of W/C was more fluid than 80% of W/C in the same P/C 80%, which increased the fillability and improved the strength, but the strength improvement effect was the greatest in adhesion in flexure. Through this study, the basic characteristics of the adhesion performance of PCCs were identified, and based on this, it is necessary to induce an optimal mixing design that can increase adhesion performance through various mixing designs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.1-4
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• 2005

This study is to examine adhesion the characteristics of self adhesive asphalt to minimize of the construction periods and the environmental problems through the performance estimation of materials to reduce waterproof problem and the long durability maintenance of building structures. This study tested the estimation items of self rubberized adhesive asphalt to examine the sheet discovered the most important problem in the construction site and the connection stability in the sheet joint. Besides, this study examined the material characteristics such as tension property, tear property, temperature dependence, heat resistance, adhesion stability and so on. Test results of the separative items satisfied in the reference figure of connection stability and adhesion stability which could confirm adhesion performances and other items also satisfied in the reference.