• Journal of KIBIM
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• v.7 no.3
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• pp.1-10
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• 2017

3D concrete printing technology builds structural components layer-by-layer with concrete extruded through a nozzle without using forms. This technology can simplify construction processes by optimizing design flexibility, construction time, and cost. Furthermore, the 3D printing technology is easy to make an irregularly shaped and function embedded building(or object) which is difficult to be constructed by conventional construction method. However, the 3D printing concrete is not suitable for current commercial standard and the material itself. It is also difficult to apply it to the construction site due to the lack of initial strength and the nozzle which is clogged during the process. The research of mix proportion design process for 3D printing concrete which differs from the conventional concrete is necessary in order to solve the problems. This paper aims to calculate the 3D printing concrete mix proportion design process based on the mix materials and performance information derived from the previous researches. Therefore, the usage variation range, mutual influence relationship, and the importance priority of the mix proportion are analyzed. Based on this results, the basic design process of 3D printing concrete which contains planning design phase, basic design phase and validating performance phase is suggested. We anticipate to confirm applicability verification about the actual production by referring to this 3D printing concrete mix proportion study. In the future, this study can be utilized for blueprint of the 3D printing concrete mix proportion.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.105-106
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• 2019

In this research, considering the practical conditions at field, thermal cracking method was suggested based on the comparative analysis between predicted value and actual value obtained from the actual structure member with optimum mix design. The optimum mix design was deduced from the various mix designs with various proportions of cementitious binder for upper and lower placement lifts of mat-foundation mass concrete. Therefore, it can be stated that applying low heat mix design and different heating technique between upper and lower placement lifts for mass concrete are efficient to control the thermal cracking. As future issues, based on the interpretation result value, we will select the optimal combination that is applied specifically to the actual site, and deeply analyze the correlation between the measured value and the analysis value through the combination and the test of the actual structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4832-4836
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• 2012

In general, there are needed lots of time and experiments for determination of optimum asphalt content and mix design. The experimental results are highly depended on the skill of testers. Bailey suggested the proper aggregate gradation of hot mix asphalt are a function of special size and passing percent of the specified aggregate to reduce the test errors. In this paper, the asphalt mix designs of 19mm dense graded mix and PA-20mm for FHWA were carried out, using Bailey's method. The use of Bailey method can cut down the testing times to get the proper aggregate gradation for asphalt mix design. In case of 19mm dense graded asphalt mixture, the measured values of CA, $FA_c$, $FA_f$ are 0.724, 0.440, and 0.455, which are within the suggested values by Bailey. Also, in case of PA-20 graded asphalt mixture, the measured values of CA, $FA_c$, $FA_f$ are 0.646, 0.476, and 0.450, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.747-750
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• 2004

Lightweight concrete is known for its advantage of reducing the self-weight of the structures, reducing the areas of sectional members as well as making the construction convenient. Thus the construction cost can be saved when applied. to . structures such as long-span bridge and high rise buildings. However, the lightweight concrete requires specific design mix method that is quite different from the typical concrete, since using the typical mix method would give rise the material segregation as well as lower the strength by the reduced weight of the aggregate. In order to avoid such problems, it is recommended to apply the design mix method of high performance self-compacting concrete for the lightweight concrete. Therefore, this study introduces a production of self-compacting concrete, PF-modified and improved version of Nan-Su's design mix method of self-compacting concrete. Through a series of test mixes conducted during the study, the quality of the concrete at its fresh condition has been evaluated per the 2nd class rating standards of self-compacting concrete published by JSCE, especially focused in its fluidity, segregation resistance ability, and filling ability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6A
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• pp.561-572
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• 2010

This paper is a study about application of recently proposed Performance Based Mixture Design (PBMD) for design of high strength concrete (HSC) to obtain HSC mix proportion that satisfies required performances. The PBMD method which uses Satisfaction curve based on a Bayesian method is a performance oriented concrete mix proportion design procedure easily applicable to any condition and environment for a possible replacement to the current prescriptive design standards. Based on extensive experimental results obtained for various materials and performance parameters of HSC, the application feasibility of the developed PBMD procedure for HSC has been verified. Also, the proposed PBMD procedure has been used to perform application examples to obtain desired target performances of HSC with optimum concrete mixture proportions using locally available materials, local environmental conditions, and available concrete production technologies. The validity and precision of HSC mix proportion design obtained using the PBMD method is verified with the experimental and ACI presented results to check the feasibility for actual design usage.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.65-73
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• 2004

Marshall stability and flow don't reflect mechanical property of asphalt mixtures and have little correlation with rutting-related performance. There is often rutting occurred on the asphalt pavement which was constructed using a mixture passing the specification for stability and flow. This study dealt with comparison of volumetric properties of mixtures from Marshall mix design and from Superpave mix design. This study used one binder, three aggregates and two gradations. The mixtures were manufactured by each mix design method. Result showed that OAC, VMA and VFA by Marshall mix design were higher than those by Superpave mix design. This is because Mashall mixture has the gradation prone to rutting and it should be further investigated whether or not the high OAC is direct cause of rutting in asphalt pavement.

• The Research Journal of the Costume Culture
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• v.17 no.4
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• pp.653-662
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• 2009

The past Romanticism, which emphasized loveful, womanish property, has changed into new-concept Romanticism as it was harmonized with various emotional cultures and trends in the 21st century. New-concept romanticism is found in various fields ranging from personality, diversity and discrimination to emotion. It is appearing as a new style searching for taste as it is mixed and matched with other fields. In fashion, Romanticism and mix-and-match trend provide womanish feeling through the match with romantic chiffon, high-waisted pants and cashmere cardigan and show modern emotion through vest and short blazer. Therefore, it is necessary to reconsider the method to analyze and express fashion emotion style on the basis of mix-and-match trend of Romanticism. The purpose of this study is to analyze how Romanticism is expressed in the mix and match with other emotional style, predict direction of Romanticism style and establish the ground to find changing fashion trend accurately. The researcher expects that design development will be focused on the fashion, which is more various and characteristic and search for convenient, healthy life, on the basis of the analysis on mix and match shown in Romanticism fashion of the study. The researcher tried to provide the base of design development and assist design activation by using mix and match, which can create various new styles, accurately and understanding and predicting the fashion trend of the 21st century.

• Korean Institute of Interior Design Journal
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• v.20 no.2
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• pp.147-155
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• 2011

The purpose of this study is to grope for plan methods through analyzing preferences on expression methods of materials for visual differentiation in hosing space. The results are as follows : First, we could know that finish material is the important element to make differential design in housing space. It is a effective method to use the color and material of finish materials. Second, we could find they preferred woods in materials and Y color, N9.5, bright and light in colors through grasping preference about types in material elements. The preferred texture is soft and the preferred patterns are solid and geometry. Third, it is a good method to mix materials which give us different season feeling, and to mix colors which are different tones to lead the differential design by materials in housing space. In case texture and patterns, what we mix similar things is the effective method. Fourth, preference of the expression method is manifested differently depending on the selected elements. so when we plan the housing, we have to consider that. lastly, I think this study will be a basic data on a study to differentiate the design of the residential space.

• Journal of the Korea Institute of Building Construction
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• v.17 no.1
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• pp.39-46
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• 2017

In this research, considering the practical conditions at field, thermal cracking reducing method was suggested based on the comparative analysis between predicted value and actual value obtained from the actual structure member with optimum mix design. The optimum mix design was deduced from the various mix designs with various proportions of cementitious binder for upper and lower placement lifts of mat-foundation mass concrete. Therefore, before field applications, the mix designs were obtained from the theoretical analysis obtained by MIDAS GEN for upper lift was OPC to FA of 85 to 15, and for lower lift was OPC to FA to BS of 50 : 20 : 30. Based on this mix design, the actual concrete for field was determined and all concrete properties were reached within the predicted range. Especially, the temperature properties of mass concrete at core was approximately $39^{\circ}C$ of temperature difference for low-heat mix design, while approximately $54^{\circ}C$ was shown for normal mix design currently used. Additionally, in the case of cracking index, the low heat mix design showed about 1.4 of relatively high value while the normal mix design showed 1.0. Therefore, it can be stated that applying low heat mix design and different heating technique between upper and lower placement lifts for mass concrete are efficient to control the thermal cracking.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.115-120
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• 1994

Recently super-flowing concrete has been developed and used in many construction sites in Japan. It is believed that super-flowing concrete will change the construction method and contribute to the durability of concrete structures. In this study the effect of mix proportion on the flowing characteristics of super-flowing concrete was investigated to establish the mix design method. From the result we have found that self-compactability of super-flowing concrete was greatly affected by the unit gravel volume and paste/gravel volume ratio. Therefore the two parameters can be used in mix design of super flowing concrete.