• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.148-149
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• 2016

In this paper, the increase in chloride resistance of footing concrete at coastal area was evaluated by replacement of Mineral Admixture. In KBC 2009, the footing concrete's minimum specific concrete strength at coastal area is determined to 35MPa. However, this is criteria only based on the strength aspect. Thus, it is not considered to increase the chloride resistance by replacement of Mineral Admixture. According to the test results of chloride ions penetration resistance, 35MPa class concrete with OPC 100% shown inaccessible state. Low-strength (24~30MPa class) concretes with Mineral Admixture, however, presented better performances. In addition, chloride diffusion coefficient tests showed identical appearance. Therefore, the current KBC's chloride resistance criteria based on only concrete strength has to review for the reason it can cause many problems (ex. cost increases by growing concrete strength and the environmental issues by a lot of cement use).

• Food Science and Industry
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• v.50 no.3
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• pp.39-50
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• 2017

In order to secure competitiveness of the home meal replacement (HMR) industry from a long-term perspective, development of packaging and processing technologies must be achieved. The development of technology that can secure freshness, nutrition, and taste but secures the shelf life is the key to the future growth of HMR. The future of HMR can be considered in terms of nutrition, environment and safety. From the nutritional point of view, it is expected that development of healthy HMR such as low-salt, low-sugar, low-fat, and high fiber and premium HMR with functional ingredient enhanced, and personalized HMR for silver, infant and patients will be done. And it is expected that development of HMR utilizing environmentally friendly food or local food, development of energy reduction and environmentally friendly disinfection technology, development of environmentally friendly packaging material, and providing information on HMR preparation using QR code and RFID from the environmental and safe point of view.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.577-580
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• 2006

This paper presents the experimental results of frost durability characteristics including freezing-thawing and de-icing salt scaling of the concrete used for gutter of the road. Mixtures were proportioned with the three level of water-binder ratio (W/B), 0.58, 0.53, and 0.48, and two binder compositions corresponding to Type I cement without any supplementary cementitious materials (OPC) and Type I cement with 30% blast-furnace slag replacement (Slag30). Also, two different solutions of calcium chloride and water that contains 0 and 8g of anhydrous calcium chloride in each 100 mL of solution, respectively, were used to evaluate their effect on the frost durability resistance. Test results showed that the Slag30 mixture exhibited higher durability factor and lower mass loss values than those made with OPC. Among the mixture tested in this work, the mixtures (OPC and Slag30) made with a relatively higher W/B of 0.58 exhibited large amount of the de-icing salt scaling regardless of calcium chloride concentration. Finally, the use of slag can be used effectively in terms of economy and frost durability of the concrete designated for gutter.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.146-154
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• 1985

Low-salted Kochuzang was made by the replacement of a part of NaCl with 4% ethanol as the preservative. Comparative analysis were performed for general components in 7 kinds of low-salted Kochuzang. The activities of ${\alpha}-and{\beta}-amylase$ and protease were high in ripened Kochuzang of low salt concentration in case of addition of alcohol. The changes of total sugar and pH were remarkably decreased when alcohol and salt were added. Total acid contents showed a remarkable increase when alcohol was not added, and in case of salt concentration. Total nitrogen contents were not remarkably changed, but the contents of amino nitrogen and ammonia nitrogen were increased in case of low salt conuntration with alcohol. Reducing sugar contents were increased in case of low salt concentration and alcohol added. Alcohol contents were not remarkably changed in case of addition of alcohol, but when alcohol was not added and low salt concentration they showed a remarkable increase(about 2.2%). A good Kochuzang may be produced by adding 4% alcohol to a low salted one (5.1% content in Kochuzang) in seventy days of the fermentation.

• Journal of the Korea Institute of Building Construction
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• v.22 no.5
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• pp.425-430
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• 2022

Concrete used for the foundation of high-rise buildings is often placed through in an integrated pouring to ensure construction efficiency and quality. However, if concrete is placed integrally, there is a high risk of temperature cracking during the hydration reaction, and it is necessary to determine the optimal mixing design of high-performance, high-durable concrete through the replacement of the admixture. In this study, experiments on salt damage, carbonation, and sulfate were conducted on the specimen manufactured from the optimal high-performance low-heating concrete combination determined in the author's previous study. The resistance of the cement matrix to chlorine ion diffusion coefficient, carbonation coefficient, and sulfate was quantitatively evaluated. In the terms of compression strength, it was measured as 141% compared to the structural design standard of KCI at 91 days. Excellent durability was expressed in carbonation and chlorine ion diffusivity performance evaluation. In particular, the chlorine ion diffusion coefficient, which should be considered the most strictly in the marine environment, was measured at a value of 4.09×E-12m²/y(1.2898×E-10m²/s), and is expected to be used as a material property value in salt damage durability analysis. These results confirmed that the latent hydroponics were due to mixing of the admixture and high resistance was due to the pozzolane reaction.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.527-530
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• 2002

In the present study, immersion test using artificial seawater was performed to evaluate the resistance of mortar specimens with or without ground granulated blast-furnace slag (SG) and fly ash (FA). Another variable was the fineness levels of SG (4,450, 6,000 and 8,000 ㎠/g). From the results of the immersion test for 270 days of exposure, the excellent resistance to seawater attack for SG mortar mixtures, especially in a high fineness levels, was confirmed. However, the reductions in compressive strength of FA mortar specimens was similar to those of OPC mortar specimens irrespective of replacement of FA.. In order to understand the deterioration mechanism due to seawater attack, X-ray diffraction (XRD) analysis were also carried out. Some reactants such as ettringite, gypsum, brucite and Friedel's salt were possibly detected through XRD technique.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.790-793
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• 2004

The factors influencing concrete deterioration in marine environment can be generally divided into the physical and chemical action. The physical attack due to drying and wetting would increase the internal stress of concrete. The chemical attack resulting from the diffusion of ions$(i,e,\;Cl^-,SO_4^{2-},Mg^+)$ from seawater through the pores in concrete. The objective of this study is to evaluate corrosion characteristics of steel when using the various concrete materials under marine exposure environment. After 3 years of exposure, concrete specimen incorporating $40\%$ blast-furnace slag as replacement for type I cement with low w/c ratio of 0.42 and using the inhibitor shows excellent performance.

• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.452-459
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• 2008

The compressed injection yellow ocher soil is the process-technology by drying the product through sunshine, not by firing like pottery and ceramic ware. It is the technology of development being able to achieve the far infrared ray and humidity adjustment by adding recycling paper, Korean paper and bamboo salt, and it corresponds with the construction enforcement ordinance 2007 as an interior-finishing product which is fire-resistant. In case that the yellow ocher soil would be used as lighting device and interior-finishing material and decoration, it could contribute to an improvement of National Health by avoiding the sick house syndrome and adding humidity adjustment, and it has more efficient economic effect due to using recycle-available additives. Through such developments of the yellow ocher soil products the domestic market of lighting device and construction material can be advanced and the replacement effect of imported goods & also export effect can be expected accordingly.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.169-172
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• 2006

The IIA structures exposed to marine environment is subject to many different types of potential attack. The physical attack due to drying and wetting would increase the internal stress of concrete. The chemical attack resulting from the diffusion of ions$(Cl^-,SO_4^{2-},Mg^+)$ from seawater through the pores in concrete. Therefore the sea water resistance of concrete must be considered when it is used for structure in the ocean. The objective of this study is to evaluate chloride diffusion and corrosion characteristics of concrete when using the various concrete materials under marine environment. After 5 years of exposure, concrete incorporating 40% blast-furnace slag as replacement for type I cement with low w/c ratio of 0.42 and using the inhibitor shows excellent performance.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.197-200
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• 2005

In this study, for the establishment of the performance evaluation methods and the quality control standards of durability recovery method, the quantitative exposure data by long term exposure test under the coast is accumulated and analyzed Investigating and evaluating the result of exposure test at 30 month of exposure age under the coastal environment, carbonation and salt damage are not happened at all but the difference in electric potential are found. Therefore, it is considered that the reinforcement corrosion at replacement with repair material are caused by active-passive corrosion macrocells.