• Title/Summary/Keyword: Paving Materials

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Utilization of Mine failings from the Jeonju-Il Mine (전주일(全州一) 금속광산(金屬鑛山) 폐광미(廢鑛尾)의 활용(活用) 방안(方案) 연구(硏究))

  • Jeong, Soo-Bok;Chae, Yeung-Bae;Hyun, Jong-Yeong;Kim, Hyung-Seok;Yoon, Sung-Moon
    • Resources Recycling
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    • v.16 no.1 s.75
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    • pp.44-53
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    • 2007
  • The Jeonju-Il mine tailings contain large quantities of $SiO_2\;and\;Al_2O_3$ and lesser quantities of metallic components. In this study, we studied about the possibility of using mine tailings as a raw material in various industries. it was found that the sintered mine tailings had a good quality in every respect such as chromaticity, firing shrinkage and water absorption etc. Therefore if can substitute clay mineral in the ceramic industry. Also it can substitute about 2.94% of the raw materials of ordinary portland cement. We can use the coarse tailing as the fine aggregate for the ready-mixed mortar; and the fine tailing, as the filler for the bituminous paving mixture; because both products were not only suitable for Korea industrial standard in quality, but also environmentally harmless.

Multi-Scale Heterogeneous Fracture Modeling of Asphalt Mixture Using Microfabric Distinct Element Approach

  • Kim Hyun-Wook;Buttler William G.
    • International Journal of Highway Engineering
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    • v.8 no.1 s.27
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    • pp.139-152
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    • 2006
  • Many experimental and numerical approaches have been developed to evaluate paving materials and to predict pavement response and distress. Micromechanical simulation modeling is a technology that can reduce the number of physical tests required in material formulation and design and that can provide more details, e.g., the internal stress and strain state, and energy evolution and dissipation in simulated specimens with realistic microstructural features. A clustered distinct element modeling (DEM) approach was implemented In the two-dimensional particle flow software package (PFC-2D) to study the complex behavior observed in asphalt mixture fracturing. The relationship between continuous and discontinuous material properties was defined based on the potential energy approach. The theoretical relationship was validated with the uniform axial compression and cantilever beam model using two-dimensional plane strain and plane stress models. A bilinear cohesive displacement-softening model was implemented as an intrinsic interface and applied for both homogeneous and heterogeneous fracture modeling in order to simulate behavior in the fracture process zone and to simulate crack propagation. A disk-shaped compact tension test (DC(T)) with heterogeneous microstructure was simulated and compared with the experimental fracture test results to study Mode I fracture. The realistic arbitrary crack propagation including crack deflection, microcracking, crack face sliding, crack branching, and crack tip blunting could be represented in the fracture models. This micromechanical modeling approach represents the early developmental stages towards a 'virtual asphalt laboratory,' where simulations of laboratory tests and eventually field response and distress predictions can be made to enhance our understanding of pavement distress mechanisms, such its thermal fracture, reflective cracking, and fatigue crack growth.

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Current Status and User Satisfaction Analysis of Neighborhood Park for Barrier Free Friendly Park - A Focus on Cheonho Park, Gandaemae Park and Hunlyunwon Park - (무장애친화공원화를 위한 근린생활권 공원의 현황 및 이용자 만족도 분석 - 천호공원, 간데메공원, 훈련원공원을 대상으로 -)

  • Kang, Hyun-Kyung;Lee, Su-Ji;Back, Seung-Jun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.1
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    • pp.135-153
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    • 2016
  • This study is aimed at grasping improvement factors of Cheonho Park, Gandaemae Park and Hunlyunwon Park as barrier free friendly parks. For this study, current status of parks, users' state and satisfaction were analyzed in October, 2014 and September, 2015. To detect current status, period of designing, whole size, facility pavement green space area, and main spaces were examined. As for BF status, mediation facilities, leading and guidance facilities, convenient facilities and BF pedestrial passage were analyzed. Also, It examined user behavior and satisfaction by accessibility, convenience and safety items. As a result of status analysis, three parks were designed in 1997~1998. The size of parks were $15,180m^2{\sim}26,697m^2$. As for mediation facilities, the slopes of walking-passage in Cheonho Park and Gandaemae Park were flat. The rate of leading-guidance facilities was 72.7%~93.4%. In the three parks, the effective width of safe pedestrian space within BF pedestrial passages was more than 1.8m. In Cheonho Park and Gandaemae Park, more than 50% of soil and urethane were used as paving materials. Users were the most satisfied with accessibilities in Cheonho Park due to flat-typed walking passages. In convenience, when it comes to using benches and pergolas, it showed significantly different satisfaction in every park. In safety, there were also considerable difference in every park. Overall, it was analysed that the satisfaction with information for safety and facilities was significantly low. Against this backdrop, this study suggests three considerations to recreate parks as barrier free friendly parks. 1) Flat-typed walking passages and enough parking areas near parks should be constructed. 2) Additional rest furniture for convenience should be installed and complemented. 3) Walking oriented-spatial safe facilities for safety should be differently supplemented.

Analysis on Urban Heat Island Effects for the Metropolitan Green Space Planning (광역적 녹지계획 수립을 위한 도시열섬효과 분석)

  • Park, Kyung-Hun;Jung, Sung-Kwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.3
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    • pp.35-45
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    • 1999
  • The research is to examine urban heat island effects which is resulted from urbanization using thermal infrared band of Landsat TM data and to demonstrate heat island alleviation effects of green spaces through correlation analysis of NDVI(Normalized Difference Vegetation Index) and surface temperature. According to the results, forests which are covered with natural vegetation have a high NDVI digital values, but surface temperature is very low, and urban areas which is composed of artificial paving materials have a low NDVI, surface temperature increases gradually. In summary, the analysis of relationship between NDVI and surface temperature, used in this study, is regarded as one of effective methodologies for proving heat island alleviation effects of vegetation.

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A Study on the Development of Color Pavement (칼라포장(鋪裝) 개발(開發)에 관한 연구(研究))

  • Kim, Ju Won;Kim, Dae Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.2
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    • pp.11-18
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    • 1982
  • The binder for hot mix type colored pavement must have the same physical qualities as the straight asphalt cement, but its color must not be dark-brown. We developed a kind of synthetic resin binder with light yellow color and confirmed its possibility as a binder for colored pavement through the several comparison tests between the straight asphalt cement concrete mixture and the mixture of binder and aggregate for colored pavement. For the pigment, it has been assured through tests that home products have the possiblities to be used. The binder has come to the stage of practical use through the trial mixing by asphalt mixing plant and the trial field placing. The mixing operation and the paving method of colored mixture are same as normal asphalt concrete mixture, but the quantity of pigment replaces that of mineral filler. The required content of pigment is decided by the trial mixing with other materials to be used.

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Evaluation of Impurity Content Criteria of Recycled Aggregate for Lean Concrete Base (빈배합 콘크리트 기층용 순환골재의 이물질 품질기준 적정성 연구)

  • Kim, Nam-Ho;Yang, Seung-Cheol
    • International Journal of Highway Engineering
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    • v.14 no.3
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    • pp.69-76
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    • 2012
  • A recent shortage in Korean aggregate market leads a social demand to utilize recycled aggregate to more advanced level, such as the use in concrete structures or paving materials for surface and base layers. Government announced a recycled aggregate guideline in 2009 to provide an institutional framework for recycled aggregate in such an up-scaled use. The use of recycled aggregate in such use; however, is very minimal. This paper evaluates the validity of the impurity content criteria of recycled aggregate for lean concrete base through a series of material tests. The analysis results shows that reclaimed asphalt pavement (RAP) in recycled aggregate not only influence a strength lean concrete adversely, but also influence negatively on an absorption and abrasion characteristics of aggregate system significantly that made those two indices lower. Since absorption and abrasion characteristics are very important indices for recycled aggregate quality, RAP in recycled aggregate could significantly mislead the recycled aggregate qualification. This paper provides a suggestion to resolve these problems.

A Study on the Fire Drill Behavior Characteristics in Rehabilitation Center for Visually Impaired Persons (시각장애인 복지관의 화재 피난행태 특성분석 연구)

  • Lee, Jeong-Soo;Kwon, Heung-Soon;Kim, Eung Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5646-5653
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    • 2015
  • This study focused on the architectural, interior and management guidelines in rehabilitation center for visually impaired persons. For these purposes, we reviewed the movement behaviors and the characteristics of fire drill in rehabilitation center for visually impaired persons. The results are as follows. : First, the liner circulation paths and interior landmarks are recommended, and dwelling units and program rooms should be located in ground floor for barrier free evacuation. Second, It is important to establish continuous handrail, variations of paving patterns and materials, good color definition, tactile informations and directional sound. Third, it is necessary to serve more specified architectural, interior, and management guidelines according to impaired prototypes.

The Development of Instructional Design Model, based on LO-Model supporting Individualized Learning (개별화학습지원-학습객체모델에 기초한 교수설계모형 개발)

  • Hong, Ji-Young;Song, Ki-Sang;Lee, Tae-Wuk
    • The Journal of Korean Association of Computer Education
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    • v.6 no.4
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    • pp.115-123
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    • 2003
  • It's difficult to find efforts for individualization other than suggesting simple, branching level learning materials among the developed courseware. The reason is primarily attributed to the facts that the courseware itself is not flexible, a fixed structure which is not reusable, and numerous costs and time should be consumed to develop one. In the same context of the appearance of the object-oriented concept in the method of software development, the concept of 'learning object' has appeared in the development of courses and contents, paving the way toward the possibility of designing versatile courses through the learning object. In the learning object-based course design, however, it still has similar shape and structure to the existing courseware, and the effort to realize the individualized learning by utilizing the learning object is not sufficient, as well. In this study, I suggest a outlined learning object model which can support the individualized learning by expanding the existing learning object, and based on th is model. design a instructional model that can show an individualized learning path, based on the ADDIE model.

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Users' Evaluation for the Trail Structures in the Dobong District of Bukhansan National Park, Korea (북한산국립공원 도봉지역 탐방로 보행시설에 대한 탐방객 평가)

  • Yoo, Ki-Joon;Cho, Woo;Cho, Keun-Sik
    • Korean Journal of Environment and Ecology
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    • v.22 no.2
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    • pp.145-151
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    • 2008
  • The purpose of this study was to understand users' attitudes for trail structure conditions in Dobong district, Bukhansan National Park, Korea. For this purpose, the research conducted a respondent's-personal entry-method based questionnaire survey on 250 visitors using inquiry routes in Dobong areas in Bukhansan National Park in July, 2007. The survey result showed that the 6 types of pedestrian trail structures were relatively in better shape in its quality and quantity while the responses for 3 types of structures, such as wood deck, wood railings, and stone paving, were positive in terms of harmony with landscape, preservation of resources, and user convenience. In conclusion, it is considered to be essential to bring in nature-friendly materials for walking facilities in National Parks and also necessary to consider the visual effect arising from the harmony with landscape together with the functions of conservation of resources and inquiry convenience.

American Women's Adoption of Pants and the Changing Definition of Femininity during World War II

  • Lee, Yhe-Young;Farrell-Beck, Jane
    • International Journal of Human Ecology
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    • v.11 no.1
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    • pp.23-33
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    • 2010
  • Articles from The New York Times and magazines including Consumer Digest, Journal of Home Economics, Scholastic, Time and Woman's Home Companion were analyzed in this study and focused on the following research questions: How did the social situation influence American women's adoption of pants during World War II? How were the social opinions of women's adoption of pants? How did American women's adoption of pants and the social opinions on women's pants represent the process of change in the definition of femininity during World War II? Women were encouraged to wear pants in work places because many women had to work in defense industries and farms. Women had to wear pants during the winter to keep warm in order to conserve oil, rubber, and other materials. In addition, wearing men's clothes became a fashion trend among college women during this period. However, practicality was often not the primary thing alone to consider in women's fashion. Femininity was still important in women's fashion. There were criticisms over the women's adoption of pants. Regulations against pants were imposed on women, while there were women who wanted to dress like ladies even at defense industries. An abrupt change in women's gender roles and the increased adoption of trousers aroused social ambivalence about the traditional definition of femininity. Even though many women returned to their homes after the war, the social demand of practicality in women's day-time clothes during the war offered women the experience of comfort and practicality in pants. These experiences contributed to paving the way for more women to adopt pants and helped establishing a new definition of femininity after the war.