• Title/Summary/Keyword: commercial concrete

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Current Research Trend on Recycling of Waste Flat Panel Display Panel Glass (폐 평판디스플레이 패널유리의 재활용 연구 동향)

  • Shin, Dongyoon;Kang, Leeseung;Park, Jae Layng;Lee, Chan Gi;Yoon, Jin-Ho;Hong, Hyun Seon
    • Resources Recycling
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    • v.24 no.1
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    • pp.58-65
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    • 2015
  • Although Korea is a top market sharing and world leading producer and developer of flat panel display devices, relevant recycling technology is not up to her prestigious status. Besides, most of the waste glass arising from flat panel displays is currently land-filled. The present paper mainly reviews on development of recycling systems for waste TFT-LCD glass from end-of-life LCD TVs and monitors and TFT-LCD process waste of crushed glass particles with target end uses of raw material for high strength concrete pile and glass fibers, respectively. Waste LCD glass was recycled to fabricate ingredients for high strength concrete piles with enhanced physical properties and spherical foam products. The waste LCD glass recycling technology is already developed to fabricate long and short fibers at commercial level. In view of these, future R & D on waste LCD glass materials is to be directed toward implementation of commercial materials recycling system therefrom.

Developing Advanced Total Recycling Method of FRP Boats (FRP선박의 일괄 재처리 방법의 개선)

  • Lee, Seung Hee;Yoon, Koo Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.1
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    • pp.53-59
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    • 2013
  • Since 1990s, the major recycling methods for mechanical recycling of FRP(Fiber Reinforced Plastics)boats has involved shredding and grinding of the scrap FRP in a new recycled product. But still it leads to secondary problem such as air pollution, unacceptable shredding noise level and few limited applications. This study is to propose a newly advanced method which is more efficient and environment friendly waste FRP regenerating system. As extracting FRP layer and making the recycled fiber for recycled-fiber reinforced concrete(RFRC) from waste FRP, the recycling process has some merits in a sense of the recycling energy and the environmental effects. In this study, for those tasks, spectro-chemical differentiation method and coloring water-soluble dye treatment makes the roving layer more distinguishable photophysically. Also that has remarkably reduced safety hazards and energy. Using the mechanical properties of polymers and composite, FRP with the orthotropic and laminated plastic structure has been easily separated in the new extracting system. Also the new method has introduced five kind of separating manuals for the some different compositions of FRP boats. The roving fiber of laminated glass-fiber layer is as good as the polyvinyl fiber which is cost-high commercial fiber to increasing strength of concrete products. The early study has shown the effectiveness of laminated glass-fiber layer which also is chemical-resistant due to the resin coating. These results imply that more efficient and environment friendly recycled glass fiber can be better applied to the fiber reinforced concrete(FRC) substitute and this study also has shown wide concrete applications with RFRC from the waste FRP boat.

Development of Spent Nuclear Fuel Transportation Worker Exposure Scenario by Dry Storage Methods (건식 저장방식별 사용후핵연료 운반 작업자 피폭시나리오 개발)

  • Geon Woo Son;Hyeok Jae Kim;Shin Dong Lee;Min Woo Kwak;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.43-52
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    • 2024
  • Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

A research on the present condition and the counteract policy of the taxation on the research funds (학술연구비 과세문제의 현황과 정책대응방안 연구)

  • Han, Sang-Wan;Choi, Myung-Keun;Lee, Chang-Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.34 no.1
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    • pp.39-70
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    • 2000
  • The government authorities holds a policy that they should impose a tax on the research funds which are judged to be profits from commercial research service among others provided for academic research and development fields. This study reveals the present condition of the research funds and suggests a counterproposal and legal complement. In concrete terms, the present condition of research funds in universities, the provisions concerned with them, opinions of Korean National Tax Service on the profits from them, problems following the provisions and policies, and the foreign taxation cases upon them are investigated. As a result, the counteract policy that research funds should be laid tax on with caution to clarify the criterion for judging whether a research service is commercial and noncommercial, and to supplement unprepared part of the legal propositions.

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The Expressional Characteristics of Interior Space for Brand Lifestyle Shop - Focused on Lifestyle Shops Opened in Seoul - (브랜드 라이프스타일 샵의 실내공간 표현특성 연구 - 서울시에 오픈한 라이프스타일 샵을 중심으로 -)

  • Lui, Run;Nam, Kyeong Sook
    • Korean Institute of Interior Design Journal
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    • v.26 no.6
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    • pp.202-209
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    • 2017
  • In 21 Century, people's living standards and material requirements have been continuously improved with the development of society. The demand for commercial space is not merely content with purchases. What's more, the consumers want to experience some activities offered by the brand while shopping. In this paper, we mainly research the spatial structure and the spatial expressional characteristics of brand lifestyle shop of Korean brands built in Seoul area. First, through the documentary research, we get the four characteristics of interior space performance of brand lifestyle shop, which are, interaction, proximity, symbolism and compound. Secondly, we select 8 brand lifestyle shops in the Seoul area as the object of this study, and analyze the actual application of the four characteristics in these cases. Thirdly, through the analysis of case study, we make a concrete analysis of the expressional characteristics of Korea's brand lifestyle shop. Finally, we reach the conclusions: First, the brand lifestyle shop provides space for both brands and consumers to communicate with each other. Second, in brand lifestyle shop there is a special space which is different from the other commercial space. The existence of this special space makes brand lifestyle shop more personalized and more specialized, and makes the customers have more interesting when they are shopping. Third, compared with the sales space, the non-sales space accounts for a larger proportion. Fourth, in spatial representation, interaction plays a role in connecting brands with consumers. Fifth, brand lifestyle shop has the same spatial concept, but it has different application and embodiment in each case. Each brand lifestyle shop has its own unique features. This is the economic strategy used by brand sustainable development and expansion.

Effects of Worm-based Extruded Pellets on Growth Performance of Olive Flounder Paralichthys olivaceus in Commercial Aquafarms (넙치(Paralichthys olivaceus)용 고효율 곤충배합사료 양식현장적용 평가)

  • Hur, Sang-Woo;Lee, Jin-Hyuk;Lee, Seunghan;Jeong, Seong-Mok;Kim, Kang-Woong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.5
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    • pp.533-540
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    • 2022
  • We evaluated a worm-based extruded pellet diet with black soldier fly Hermetia illucens larvae (BSF) meal and BSF oil for olive flounder Paralichthys olivaceus through field feeding experiments at a commercial aquafarm. We prepared two experimental diets by replacing fish meal and fish oil with BSF meal and BSF oil (BEP-1, BSF meal 7%, BSF oil 1%) and (BEP-2, BSF oil 2%), respectively. We prepared raw-fish based moist pellets (MP) for comparison between the two experimental diets. We distributed the olive flounder (220±6.29 g) in square (10 m×10 m×1 m) concrete, 100 ton tanks at a density of 1,600 fish per tank (n=3) in triplicate for each dietary treatment. We fed the diets to the fish to apparent satiation for 7 months. At the end of the feeding trial, we found no substantial differences between the groups in terms of growth performance, survival, or feed utilization. None of the diet groups showed any changes in either hematological or non-specific immune responses. The histological observation of the intestine showed that the goblet cell number and cholecystokinin-producing cell activity increased in the fish fed the BEP diet compared with the those of the fish fed the MP diet. These results indicated that dietary BSF meal and oil can be used for olive flounder without compromising growth or, hematological and histological parameters.

Mock-up Test of Temperature Crack Reduction Method Application by Setting Time Control of Mat Foundation Mass Concrete (응결시간조정에 의한 매트기초 매스 콘크리트의 온도균열저감 공법적용의 Mock-up Test)

  • Han, Cheon-Goo;Lee, Jae-Sam;Noh, Sang-Kyun
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.55-61
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    • 2009
  • Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

Static Behavior Analysis of Spillway Pier for Dam Safety Evaluation (댐 안전성 평가를 위한 여수로 피어부의 정적 거동 분석)

  • Jang, Bong-Seok;Lim, Jeong-Yeul;Lee, Myung-Kue;Lee, Hyung-Jun
    • Journal of the Korea Concrete Institute
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    • v.19 no.1
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    • pp.11-18
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    • 2007
  • Seismic performance evaluation for dam safety evaluation has been continually conducted. However the behavior analysis for the spillway pier which is known as the weak point of dam is seldom reported. Therefore, this study performed the static loading tests for a prototype structures as elementary tests for the final seismic performance evaluation of dam safety. The prototype of pier structure has 1/20 scale and it adopts to strength model. And cracking loads and ultimate loads of real structures are calculated through numerical analysis using commercial FEM program (ABAQUS). The results of this study show some difference between the results of prototype tests and the results of numerical analysis. Also, the ultimate and cracking loads can be estimated through the prototype loading test and numerical analysis.

Characteristics of Flexural Capacity and Ultrasonic in RC member with Corroded Steel and FRP Hybrid Bar (부식된 FRP Hybrid Bar의 휨 내력 및 초음파 속도 특성)

  • Choi, Se-Jin;Mun, Jin-Man;Park, Ki-Tae;Park, Cheol-Woo;Kwon, Seung-Jun
    • The Journal of the Korea Contents Association
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    • v.15 no.8
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    • pp.397-407
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    • 2015
  • Concrete is a attractive construction material, however durability problem occur due to steel corrosion, which leads propagation to structural safety problem. The recently developed FRP (Fiber Reinforced Plastic) Hybrid Bar has an engineering merit of both structural steel and FRP. Accelerated corrosion test for RC (Reinforced Concrete) samples with normal steel and FRP Hybriud Bar are performed and their flexural capacity is evaluated. Furthermore UV(Ultrasonic Velocity) measurement is attempted for analysis of variation of UV due to corrosion condition. After corrosion test, there is no significant reduction in RC beam with FRP hybrid bar but 11.5% of reduction in the case of normal steel is evaluated with 3.3% of UV reduction. For commercial production of FRP hybrid bar, bond strength evaluation through long-term submerged corrosion is required.

Shear lag effects on wide U-section pre-stressed concrete light rail bridges

  • Boules, Philopateer F.;Mehanny, Sameh S.F.;Bakhoum, Mourad M.
    • Structural Engineering and Mechanics
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    • v.68 no.1
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    • pp.67-80
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    • 2018
  • Recently, U-section decks have been more and more used in metro and light rail bridges as an innovative concept in bridge deck design and a successful alternative to conventional box girders because of their potential advantages. U-section may be viewed as a single vent box girder eliminating the top slab connecting the webs, with the moving vehicles travelling on the lower deck. U-section bridges thus solve many problems like limited vertical clearance underneath the bridge lowest point, besides providing built-in noise barriers. Beam theory in mechanics assumes that plane section remains plane after bending, but it was found that shearing forces produce shear deformations and the plane section does not remain plane. This phenomenon leads to distortion of the cross section. For a box or a U section, this distortion makes the central part of the slab lagging behind those parts closer to the webs and this is known as shear lag effect. A sample real-world double-track U-section metro bridge is modelled in this paper using a commercial finite element analysis program and is analysed under various loading conditions and for different geometric variations. The three-dimensional finite element analysis is used to demonstrate variations in the transverse bending moments in the deck as well as variations in the longitudinal normal stresses induced in the cross section along the U-girder's span thus capturing warping and shear lag effects which are then compared to the stresses calculated using conventional beam theory. This comparison is performed not only to locate the distortion, warping and shear lag effects typically induced in U-section bridges but also to assess the main parameters influencing them the most.