• 한국도로학회:학술대회논문집
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• 1999.11a
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• pp.89-96
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• 1999

• Steel and Composite Structures
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• v.41 no.5
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• pp.731-746
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• 2021

The purpose of this paper is to investigate the axial bearing capacity and residual properties of steel reinforced recycled aggregate concrete (SRC) column after elevated temperature. A total of 48 SRC columns were designed for the static loading test after elevated temperature. The variables include replacement ratios, designed temperature, target duration, thicknesses of cover concrete, steel ratios and stirrup spacing. From this test, the mass loss ratio and stress load-deformation curve were obtained, and the influence of various parameters on residual bearing capacity were analyzed. ABAQUS was used to calculate the temperature field of specimens, and then got temperature damage distribution on the cross-section concrete. It was shown that increasing of the elevated temperatures leaded to the change of concrete color from smoky-gray to grayish brown and results in reducing the bearing capacity of SRC columns. The axial damage and mechanism of SRC columns were similar to those of reinforced natural aggregate concrete columns at the same temperatures. Finally, the calculation method of axial compressive residual bearing capacity of SRC columns recycled concrete columns after high temperature was reported based on the test results and finite element analysis.

• Archives of design research
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• v.11 no.3
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• pp.199-206
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• 1998

Though development of semantic ratings of color image which is objective, concrete and reflecting our realities is urgent, researches on the area has not been active. To develop concepts and methods on semantic ratings of color image, study subjects, sampling, stimulating tools, analysis methods, and evaluation scale were critically reviewed on the literatures on color image. Planning color of costume commodity requires research on various themes and expanding study subjects into a variety of social strata. According to the context of study, stimulating tools should be selected prudenly, and analysis methods should be scrutinized. Factor analysis was used frequently as analysis method to extract factors associated with color image.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.2
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• pp.17-29
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• 2003

This survey paper examines general characteristics of "yellow" color, the oldest color in the history of art. Also the research aims to find meanings of the color and historical development embedded in clothing and textile both in orient and in occident where different philosophy and history developed. It is found here that the yellow symbolized both positive and negative meaning in the history of costume throughout the world. The color, however, was used to symbolize mostly positive meaning in the orient whereas not in the occident. "Yellow" color in orient used to symbolize the supremacy of the emperor, excellence and authority. The meaning of "yellow" color in the occident is two fold: from the positive viewpoint it represent god, king, wisdom, wealth and holy light, and from the negative viewpoint it represent image of betrayal and distrust, image of immorality, image of death and disease and image of jealousy and hatred. The concept of "yellow" was generalized in orient by the "Eum-Yang-O-Haeng Theory", while in occident by the Christianism. And the concepts came to hold concrete meanings and thereafter the symbol of yellow appeared.ings and thereafter the symbol of yellow appeared.

• Resources Recycling
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• v.11 no.5
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• pp.24-29
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• 2002

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, the quality control technologies especially about color were investigated on the spray roaster and iron oxide powder. At the operation condition of the spray roaster, the charge amount of waste acid per hour, temperature, numbers of spray nozzle were investigated. At admixing process, titanium oxide, silica, goethite were tested. Color character of iron oxide can be improved by process control at spray roaster and by admixing process at a pigment factory Iron oxide from results of this study is enough to use as the colorant of concrete product.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.144-148
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• 2001

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, quality control technologies to improve color were investigated. During operation of the spray roaster, the charge amount of waste acid per hour, temperature, and numbers of spray nozzles were investigated. At the admixing process, titanium oxide, silica, and goethite were tested. The color character of iron oxide can be improved by process control of the spray roaster and the admixing process at a pigment factory. Iron oxide from this study is appropriate for use as a colorant of a concrete product.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.98-103
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• 2017

In Korea, the guideline for the bridge safety inspection requests to assess surface degradation, including crack, efflorescence, spalling, and so on, for the rating of concrete bridges. Currently, the assessment of efflorescence is performed based on the visual inspection of expertized engineers, which may result in subjective inspection result. In this study, a novel method using a hyperspectral camera is proposed for objective and accurate assessment of concrete efflorescence. The hyperspectral camera acquires the light intensity for a number of continuous spectral bands of light for each pixel in an image, which makes the hyperspectral imaging technique provides more detailed information than a color camera that collects intensity for only three bands corresponding to RGB (red, green, and blue) colors. A stepwise assessment algorithm is proposed based on the spectral features to decompose efflorescence area from the inspected concrete area. The algorithm is tested in the laboratory test using two concrete specimens, one of which is dark colored with efflorescence on a surface while the other is bright concrete without efflorescence. The test shows high accuracy and applicability of the proposed efflorescence assessment using a hyperspectral camera.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.89-94
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• 2004

Most reinforcements in concrete are constructed by steel. Corrosion of reinforcement is the main cause of damage and early failure of reinforced concrete structures. The corrosion is mainly professed by the chloride ingress. In general, chloride in concrete can be discriminated by two components, total chloride and fire chloride. This paper provides a testing method on the coefficient of chloride diffusion in concrete and the relationship between total chloride and free chloride in concrete for the composition of predicting model on diffusion rate of chloride. In order to complete this predicting model, this study will use chloride penetration characteristic, diffusion coefficient and experiment of color change on silver nitrate solution. This predicting model is going to help that grasp special quality on salt content inclusion of concrete structure that is exposed in chloride environment. Accurate predicting model can be effectively used not only in selecting of repair time but also in preventing from various deteriorations.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.195-201
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• 2008

When reinforced concrete is subjected to high temperature as in fire, there is deterioration in its properties of particular importance are loss in compressive strength, cracking and spalling of concrete, destruction of the bond between the cement paste and the aggregates and the gradual deterioration of the hardend cement paste. Assessment of fire-damaged concrete usually starts with visual observation of color change, cracking and spalling of the surface. In this paper, it was reported the trends of research and practical use on the Explosive Spalling Properties of the High-Strength Concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.49-52
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• 2005

This study was performed to evaluate antibacterial performance antibiotics(RCF-95, Antibio-C) which could control biochemical corrosion of concrete used sewage facilities by sulfate oxidizing bacteria. As antibacterial methods, Broth MIC testing was used for investigating controlled growth effect of sulfate oxidizing bacteria. Also, color-changed testing by indicator was used for confirming between $H_{2}SO_{4}$ diffusion rate by bacteria and antibiotics. It confirmed that Antibio-C was superior to RCF-95 in the antibacterial performance and hence anticipated that this developed Antibio-C was enough to replace imported antibiotics from Japan.