• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1994.05a
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• pp.223-223
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• 1994

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.1-9
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• 2012

This study aims to propose a performance metric for the application of a horizontal air-exhausting system to be used for the reduction of vapor and/or moisture that exists in the waterproof layer, by evaluating the physical properties. For this reason, tests in accordance with current standards were carried out, and the results were examined. Finally, a proposal was established for a general performance metric that could be applied as fundamental data based on the user's judgment. This has some limitations, in that the object is existing merchandise, however it should be useful for application in the construction field. In the future, analysis of a wider area, including workability, should be added in the phase of field application.

• Elastomers and Composites
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• v.36 no.1
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• pp.37-43
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• 2001

Influence of the filler composition ratio on cure characteristics and bound rubber content of the compounds and on physical properties of the vulcanizates were studied using both silica and carbon black-filled styrene-butadiene rubber (SBR) compounds with the total filler content of 80.0 phr. The bound rubber content increased slightly with increase of the silica content ratio. The viscosity also increased with increasing the silica content ratio, especially increased steeply after the silica content of 60.0 phr. The cure times obtained with a rheometer, t2, t40, and t90, are increased by increasing the silica content ratio and the cure rate decreased. The delta torque increased with the increased silica content ratio. Variation or the modulus with the silica content ratio showed a decreased trend though the delta torque increased. The tan ${\delta}$ at $60^{\circ}C$ decreased with increased of the silica content ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.489-492
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• 2008

Adiabatic temperature rise and autogenous shrinkage experiments were performed for three silica-fume included mass concrete mixtures and a reference mixture without silica-fume, in order to investigate the influence of silica-fume on the hydration heat and autogenous shrinkage properties of mass concrete, and to examine applicability of silica-fume to mass concrete. It was revealed from the experiment that, for mass concrete, the rate of hydration was hardly increased while the maximum adiabatic temperature rise decreased about 5$^{\circ}$C by the addition of silica-fume, and the amount of autogenous shrinkage was almost the same regardless of silica-fume replacement. These facts imply that silica-fume can enhance the resistance of mass concrete to temperature cracking as well as the durability.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.813-816
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• 2008

This study is an experimental study on the properties and efficiency of mold-prevention mortar and the results are summarized as following. The flow, compressive stress, and the drying shrinkage ratio of mold-prevention mortar was similar with plain, so it was shown that the mold-prevention does not influence physical effect specially. However, the mold-prevention mortar which even mixed with few mold, the mold-prevention capacity greatly increased. Also, the mold-prevention capacity of 1:4 ratio mortar was better than 1:2 ratio mortar.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.133-145
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• 1984

To study the effect of foaming agent on the characteristic of mortar, the tests of water-cement ratio and bulk density of mortar were done under the different mixing ratio with G. U and J foaming agents. The results obtained were summarized as follows: 1. At the mixing ratio of 1 : 4 and 0.5% of foaming agent, the highest water-cement ratio was 90% by G, 88.3% by U and 70% by J foaming agent, respectively, being lower than 91.6% of that of cement mortar. 2. At the mixing ratio of 1 : 3 and 3.0% of foaming agent, the water-cement ratio was decreased up to 22.0% by G and 24.1% by U foaming agent, respectively, but it gradually was increased in richer and poorer mixing ratio. At the mixing ratio of 1 : 4 and 3.0% of foaming agent, the water-cement ratio was decreased up to 53.1% by J foaming agent, but it gradually was increased in richer mixing ratio. 3. At the mixing ratio of 1 : 1 and 0.5% of foaming agent, the highest bulk density was $1.981g/cm^3$ by G, $1.863g/cm^3$ by U and $1.149g/cm^3$ by J foaming agent, respectively, being lower than $2.048g/cm^3$ of that of cement mortar. 4. At the mixing ratio of 1 : 2 and 3.0% of foaming agent, the bulk density was decreased up to 20.7% by G, 23.7% by U and 56.5% by J foaming agent, respectively, but it gradually was increased in richer and poorer mixing ratio. 5. The water-cement ratio and bulk density were decreased in more addition of foaming agent, respectively, multiple regression equations of water-cement ratio and bulk density were computed depending on a function of mixing ratios and addition of foaming agents.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.395-405
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• 2016

The thermal and mechanical properties of fiber-reinforced mortars for thermal energy storage were investigated in this paper. The effect of the combination of different cementitious composite on the thermal and mechanical characteristics of fiber-reinforced mortars was investigated. Experiments were performed to measure mechanical properties including compressive strength before and after thermal cycling and split tensile strength, and to measure thermal properties including thermal conductivity and specific heat. The results showed that the residual compressive strength of mixtures with OPC and graphite was greatest among the mixtures. Thermal conductivity of mixtures with alumina cement was greater than that of mixtures with OPC, indicating favor of alumina cement for charging and discharging in thermal energy storage system. The addition of zirconium into alumina cement increased specific heat of mixtures. Test results of this study could be used to provide information of material properties for thermal energy storage concrete.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.387-394
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• 2016

This study was evaluated that fundamental quality properties in the mortar level, as part of a basic study for development of fiber reinforced concrete using basalt fiber. Mortar mixtures used in the experiments used the mortar using cement only and high volume fly ash mortar using fly ash of 50%, was evaluated by comparison. As a experiments results, high volume fly ash mortar using 50% fly ash was effective for improving fiber dispersibility than mortar using cement only, accordingly, it showed that fiber aggregation phenomenon has been greatly reduced. In addition, if the fly ash used much more than 50%, the compressive strength has been shown to decrease of about 30%, fiber length and mixing ratio of basalt fiber was found to have a greater effect on flow properties than mechanical properties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.219-224
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• 2013

In this study, the inorganic insulating material was fabricated with quartzite, ordinary portland cement(OPC), lime and anhydrous gypsum. After characteristic analysis of slurry, the optimum mixing ratio was derived with different $CaO/SiO_2$ mole ratio. Based on derived mixing ratio, the inorganic insulating material was fabricated at different water content and hydrothermal synthesis conditions. Specific gravity was $0.26g/cm^3$, compressive strength was 0.4 MPa, and thermal conductivity was 0.064 W/mK. This properties were enhanced performance of conventional ALC (Autoclaved Lightweight Concrete). And it can replace organic insulation with harmless inorganic insulation through continues research and development.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.3
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• pp.59-67
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• 2007

For the time being, HMA test specimen were prepared by Marshall Compaction Method for hot mix asphalt design and evaluated the mechanical properties of HMA at the specified air voids. Gyratory Compaction can simulate the field compaction process and measure the degree of compaction just after field compaction in laboratory. Superpave mix design with Gyratory compactor has been used for characterization of performance. The curve of gyratory compaction can be used to evaluate the permanent deformation potential of hot mix asphalt. In this paper, couple of indices for hot mix asphalt have been showed for hot mix asphalt in Korea. The major properties from gyratory compaction curve are compaction energy index and traffic compaction index. The specific guide line for the potential of hot mix asphalt has been proposed.