• Title/Summary/Keyword: green concrete

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Planting Design Strategy for a Large-Scale Park Based on the Regional Ecological Characteristics - A Case of the Central Park in Gwangju, Korea - (지역의 생태적 특성을 반영한 대형공원의 식재계획 전략 - 광주광역시 중앙근린공원을 사례로 -)

  • Kim, Miyeun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.3
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    • pp.11-28
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    • 2021
  • Due to its size and complex characteristics, it is not often to newly create a large park within an existing urban area. Also, there has been a lack of research on the planting design methodologies for a large park. This study aims to elucidate how ecological ideas can be applied to planting practice from a designer's perspective, and eventually suggest a planting design framework in the actual case, the Central Park in the City of Gwangju. This framework consists of spatial structure of planting area in order to connect and unite the separated green patches, to adapt to the changes of existing vegetation patterns, to maintain the visual continuity of landscape, and to organize the whole open space system. The framework can be provided for the spatial planning and planting design phase in which the landscape designer flexibly uses it with the design intentions as well as with an understanding of the physical, social, and aesthetic characteristics of the site. The significance of this approach is, first that it can maintain ecological and visual consistency of the both existing and introduced landscapes as a whole in spite of its intrinsic complexity and largeness, and second that it can help efficiently respond to the unexpected changes in the landscape. In the case study, comprehensive site analysis is conducted before developing the framework. In particular, wetlands and grasslands have been identified as potential wildlife habitat which critically determines the vegetation patterns of the green area. Accordingly, the lists of plant communities are presented along with the planting scheme for their shape, layout, and relations. The model of the plant community is developed responding to the structure of surrounding natural landscape. However, it is not designed to evolve to a specific plant community, but is rather a conceptual model of ecological potentials. Therefore, the application of the model has great flexibility by using other plant communities as an alternative as long as the characteristics of the communities are appropriate to the physical conditions. Even though this research provides valuable implications for landscape planning and design in the similar circumstances, there are several limitations to be overcome in the further research. First, there needs to be more sufficient field surveys on the wildlife habitats, which would help generate a more concrete planting model. Second, a landscape management plan should be included considering the condition of existing forest, in particular the afforested landscapes. Last, there is a lack of quantitative data for the models of some plant communities.

The Characteristics of Retention and Evapotranspiration in the Extensive Greening Module of Sloped and Flat Rooftops (저토심 경사지붕과 평지붕 녹화모듈의 저류 및 증발산 특성)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.107-116
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    • 2013
  • This study was undertaken to investigate the characteristics of retention and evapotranspiration in the extensive greening module of sloped and flat rooftops for stormwater management and urban heat island mitigation. A series of 100mm depth's weighing lysimeters planted with Sedum kamtschaticum. were constructed on a 50% slope facing four orientations(north, east, south and west) and a flat rooftop. Thereafter the retention and evapotranspiration from the greening module and the surface temperature of nongreening and greening rooftop were recorded beginning in September 2012 for a period of 1 year. The characteristics of retention and evapotranspiration in the greening module were as follows. The water storage of the sloped and flat greening modules increased to 8.7~28.4mm and 10.6~31.8mm after rainfall except in the winter season, in which it decreased to 3.3mm and 3.9mm in the longer dry period. The maximum stormwater retention of the sloped and flat greening modules was 22.2mm and 23.1mm except in the winter season. Fitted stormwater retention function was [Stormwater Retention Ratio(%)=-18.42 ln(Precipitation)+107.9, $R^2$=0.80] for sloped greening modules, and that was [Stormwater Retention Ratio(%)=-22.64 ln(X)+130.8, $R^2$=0.81] for flat greening modules. The daily evapotranspiration(mm/day) from the greening modules after rainfall decreased rapidly with a power function type in summer, and with a log function type in spring and autumn. The daily evapotranspiration(mm/day) from the greening modules after rainfall was greater in summer > spring > autumn > winter by season. This may be due to the differences in water storage, solar radiation and air temperature. The daily evapotranspiration from the greening modules decreased rapidly from 2~7mm/day to less than 1mm/day for 3~5 days after rainfall, and that decreased slowly after 3~5 days. This indicates that Sedum kamtschaticum used water rapidly when it was available and conserved water when it was not. The albedo of the concrete rooftop and greening rooftop was 0.151 and 0.137 in summer, and 0.165 and 0.165 in winter respectively. The albedo of the concrete rooftop and greening rooftop was similar. The effect of the daily mean and highest surface temperature decrease by greening during the summer season showed $1.6{\sim}13.8^{\circ}C$(mean $9.7^{\circ}C$) and $6.2{\sim}17.6^{\circ}C$(mean $11.2^{\circ}C$). The difference of the daily mean and highest surface temperature between the greening rooftop and concrete rooftop during the winter season were small, measuring $-2.4{\sim}1.3^{\circ}C$(mean $-0.4^{\circ}C$) and $-4.2{\sim}2.6^{\circ}C$(mean $0.0^{\circ}C$). The difference in the highest daily surface temperature between the greening rooftop and concrete rooftop during the summer season increased with an evapotranspiration rate increase by a linear function type. The fitted function of the highest daily surface temperature decrease was [Temperature Decrease($^{\circ}C$)=$1.4361{\times}$(Evapotranspiration rate(mm/day))+8.83, $R^2$=0.59]. The decrease of the surface temperature by greening in the longer dry period was due to sun protection by the sedum canopy. The results of this study indicate that the extensive rooftop greening will assist in managing stormwater runoff and urban heat island through retention and evapotranspiration. Sedum kamtschaticum would be the ideal plant for a non-irrigated extensive green roof. The shading effects of Sedum kamtschaticum would be important as well as the evapotranspiration effects of that for the long-term mitigation effects of an urban heat island.

Evaluation Method of Self-healing Performance of Cement Composites (시멘트 복합체의 자기치유 성능평가 방법)

  • Lee, Kwang-Myong;Kim, Hyung-Suk;Min, Kyung-Sung;Choi, Sung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.134-142
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    • 2020
  • In this study, in order to evaluate the self-healing performance of cement composites the self-healing test method and the analysis method were suggested by applying constant water head permeability test, chloride migration test and repeated bending test. The method of making a cracked specimen and controlling crack width are also proposed. Constant head water permeability test can evaluate the healing performance by using the decreasing rate of water flow passing through the crack zone of a specimen. Furthermore, the equivalent crack width can be used to intuitively investigate the healing effect with healing period. The chloride migration test can evaluate the healing rate by the decreasing rate of the diffusion coefficient obtained by ASTM C 1202. Mechanical healing performance can be evaluated using ISR and IDR estimated from load vs. CMOD relationship graph obtained through the repeated bending test. Finally, the applicability of proposed self-healing evaluation methods was examined by testing mortar specimens with or without self-healing agents.

A basic study on the creation of historic revolutionary sites in North Korea (북한의 혁명사적지 및 혁명전적지 형성에 관한 기초연구)

  • 김동찬;안봉원;서주환;김광래;김신원
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.4
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    • pp.61-80
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    • 1996
  • This research study presents historic revolutionary sites in North Korea. In this study, the creation of historic revolutionary sites in North Korea after the Liberation of Korea in 1945, as yet unpublished in the field of landscape architecture and urban planning, is investigated. For conducting this study, the method of true and urban planning, is investigated. For conducting this study, the method of archival research, in which regarding documents, plans and photographs are investigated, was used. This study covers notions, establishment, related laws and regulations, distribution and present status, developmental stages, concrete examples, and general characteristics, of historic revolutionary sites in North Korea. In North Korea, historic revolutionary sites mean all the places where revolutionary achievements of Kim, Ill-Sung and his family are reached. Those sites have been actively created for the purpose of the idolization of Kim, Ill-Sung since the 1960s. In recent years, the sites have been revobated and new places of this kind have been constructed, so that various idolization facilities and structures are now everywhere in North Korea. Historic revolutionary sites are mainly distributed now everywhere in North Korea. Historic revolutionary sites are mainly distributed now everywhere in North Korea. Historic revolutionary sites are mainly distributed in Pyungyang, the forest areas of Mt. Pakdu, the areas along the shore of the Tuman River and the Abrock River. In those sites, various historic revolutionary relics are preserved, and the statues of Kim, Ill-Sung, historic revolutionary monuments, revolutionary museums and other facilities are constructed. These places can not be regarded as planned spaces for people in true the meaning of place, and accordingly they must be reconstructed for people's use. They can be redeveloped as places of history, culture and deucation, theme parks, green open spaces, and sight-seeing facilities after unification of Korea. This study can be used as valuable information for further study especially for the reconstruction planning of the places in preparation for a probable unified Korea. For a profound study, North Korea must open broader and more accurately detailed documents, regarding historic revolutionary sites, to the outside world, and the South Korean Government must also have a sense of co-ownership of the information about North Korea rather than exclusive possession and restrictions. Ultimately, academic exchange between South and North Korea must be realized and on-the-spot surveys must be carried out so as to find a reasonable land use plan for the historic revolutionary sites for a future unified Korea.

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Reduction Effect on Surface Temperature of Reinforced Soil Wall with Vegetated Facing (전면 식생형 보강토 옹벽의 표면온도 저감 효과)

  • Jung, Sunggyu;Lee, Kwangwu;Cho, Samdeok;Kim, Juhyong
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.12
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    • pp.53-60
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    • 2013
  • A new type of reinforced earth wall(REW) system is developed with vegetated facing which provides proper environment for long-term vegetation and also applicable to high retaining wall system. Vegetated retaining wall is a green alternative for retaining walls and an effective way to reduce heat island effect than conventional block or concrete systems. Several construction sites using vegetated facing is observed to monitor adaptation state of vegetation and estimate surface temperature of wall facing over two years. It was observed that a number of plants including Siberian chrysanthemum adapt well to the inside of the facing blocks because vegetation bag helps to keep a proper condition for vegetation. According to the results using thermographic camera, average surface temperature of vegetated facing is higher for all ranges of coverage ratio of vegetation. The increment of average surface temperature of vegetated facing is larger than that of non-vegetated facing when the air temperature rises, and vice versa.

Life Cycle Assessment of Timber Arch-Truss Bridge by Using Domestic Pinus rigida Glued-Laminated Timber (리기다소나무 구조용 집성재를 활용한 아치 트러스 목조교량의 전과정평가)

  • Son, Whi-Lim;Park, Joo-Saeng;Kim, Kwang-Mo
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.1-12
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    • 2014
  • This study carried out life cycle assessment for evaluating environmental impacts of timber Arch-Truss bridge by using domestic Pinus rigida Miller glued-laminated timber throughout life cycle such as extraction, manufacturing, transportation, construction, use, dismantlement, transportation of waste, disposal and recycling. The life cycle GHG (GreenHouse Gas) emissions of the target bridge are 192.56 ton $CO_2$ eq. in 50 years. Especially, the life cycle GHG emissions of concrete used in the target bridge are 82.84 ton $CO_2$ eq. which accounts for 53.02% of the GWP (Global Warming Potential) in extraction and manufacturing stages. The target bridge is constructed of $116.57m^3$ of domestic Pinus rigida Miller glued-laminated timber and used timber has stored 104.72 ton $CO_2$. If an effect of carbon storage in timber is applied to the total GHG emissions of the target bridge, the GHG emissions can be reduced by 54.38%. In the case of substitution effect, if domestic Pinus rigida Miller glued-laminated timber replaces steel manufactures used in other bridge which has the same structure and life span as the target bridge, the GHG emissions in extraction and manufacturing stages can be reduced by 10.26% to 23.91%.

Water Permeability Performance Evaluation of Mortar Containing Crack Self-healing Mineral Admixtures (균열 자기치유 재료 혼입 모르타르의 투수성능 평가)

  • Lee, Woong-Jong;Hwang, Ji-Soon;Ahn, Sang-Wook;Lee, Kwang-Myong
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.463-469
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    • 2016
  • In this paper, compressive strength and water permeability performance for two types of crack self-healing materials such as SH-PO-0 composed of mineral admixtures(expansive agent, swelling material and crystal growth agent) and SH-PO-(5, 15, 30) blended with SH-PO-0 and phosphate additive(PO) dissolving easily calcium ion, were evaluated. The test results show that the water flow of SH-PO-0 decreased steeply at the early age although compressive strength decreased about 9% at 28 days compared with OPC. The higher PO replacement ratio is, the lower compressive strength and more improved water permeability performance is, and thus, based on such results, adequate PO replacement ratio is 15%. It is also found that the self-healing performance of SH-PO-15 was quite improved at the early ages and however, the performance of SH-PO-15 is similar to one of SH-PO-0 at long-term ages, and 28 days compressive strength of SH-PO-15 decreased about 8% compared with SH-PO-0. In addition, it is confirmed from the analysis of SEM-EDS that calcium ions of SH-PO-15 were crystallized more than those of SH-PO-0.

Emission Characteristics of Volatile Organic Compounds from Building Flooring Materials (건축용 바닥재로부터의 휘발성유기화합물 방출특성)

  • Yun, Joong-Seop;Lee, Myong-Hwa;Eom, Seok-Won;Kim, Min-Young;Kim, Jong-Ho;Kim, Shin-Do
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.10
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    • pp.973-978
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    • 2010
  • The emission of volatile organic compounds (VOCs) from building materials is one of great concerns due to maintain airtight condition of a building to reduce energy consumption, and it causes the deterioration of indoor air quality. Therefore, the emission characterization of VOCs from building materials is necessary to improve indoor air quality. Emission characteristics of VOCs from a plywood flooring that is one of the most commonly used materials in an under-heating system, and from an adhesive that is generally used to stick a plywood flooring to a concrete floor were investigated using an emission chamber test in this study. It was found that the VOCs emission factor was dependent upon and proportional to indoor temperature, and the emission characteristics were closely related to the existing places and conditions of VOCs sources inside the building materials. Maximum emission factors of hexane and toluene from building materials were generally observed at the beginning, however, only that of toluene from a plywood flooring was shown after 6 hours from the beginning. It could be considered that the existing place and condition of toluene source inside a plywood flooring could influence on the VOCs emission. From this study, bake-out time more than 72 hours could be recommended before moving in to avoid the exposure to high concentration of VOCs emitted from an under-heating system.

The Analysis of the Influential Factors on Design Trends and Color Trends in the Late 20th Century (20세기 후반 디자인 트렌드의 형성요인과 색채 트렌드 분석)

  • Kim, Hyun-Kyung;Kim, Young-In
    • Archives of design research
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    • v.20 no.1 s.69
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    • pp.5-20
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    • 2007
  • The aim of this research is to find out the flows of mega-trends and design trends by analyzing the factors that influence trend and design trends in the late 20th century. Moreover, it is to forecast and recommend design color trends by evaluating color trends in design trends for the near future. Secondary and primary research were used in parallel. In the late 20th century, mega-trends were analyzed from secondary research based on PEST. Design trends were analyzed from case studies in fashion, space, product and visual design. On this basis, design color trends were analyzed. Also, color trends were forecast for the near future. The results are as follows. Firstly, the main trends in the late 20th century were 'female thinking', 'back to the nature' and 'heaven of peace'. Second, main design trends in the 1970s were modernism, post-modernism and high-tech. In the 1980s, with those of the 1970s, ecology was introduced In the late 1980s. In the 1990s, modernism rose again and ecology had an influence. The trends of 'female thinking' and 'back to the nature' controled the design in the early 2000s. Third, design colors in the late 20th century changed from Red to Purple Blue. Tones changed from 'grayish' to 'dull' Finally, it was forecast that Purple Blue, Yellow Red and Green colors with 'grayish', 'dull' and 'deep' tones were going to be used mainly in the near future. Also, achromatic colors with female and warm nuances would be reflected in design parts. This research will be very useful in that it has built a concrete database reflected on design trends forecasting in the near future by organizing academically a methodology to identify trends reflected on design and identifying relation between mega-trends and design trends based on analyzing factors that influence trend.

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Type and Characters of Agricultural Injury Subjective Burden (농작업 손상에 대한 주관적 부담의 종류 및 특성)

  • Youn, Kanwoo;Im, Sanghyuk;Park, Jinwoo;Lee, Kyungsuk;Chae, Hyeseon
    • Journal of agricultural medicine and community health
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    • v.41 no.1
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    • pp.1-12
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    • 2016
  • Objectives: In establishing policies for agricultural safety, evaluating injury burdens as well as investigating the rates and characteristics of work injury is important. This study investigated the types and characteristics of agricultural injury subjective burdens. Methods: By analyzing the injured farmers identified in the 2013 Korean Farmers' Occupational Injury Survey, the burdens caused by injuries were categorized using one direct cost item (medical costs) and five indirect cost items (including productivity decreases and wage increases). Statistical differences among the burden items were analyzed using logistic regression analysis according to the characteristics of the farmers and their farm injuries. Results: Among the subjective burdens indicated by the 457 injured farmers, disruption to work was most common. The major influences on each subjective burden item are as follows: for the item of disruption to work, age, time of injury occurrence, treatment period, and farming machine use were influential; for an increased family member's burden of farm works, the number of family members and treatment period were influential. Regarding cost burden of treatment, the results varied according to whether or not the patient was hospitalized and annual income. Conclusion: Subjective burdens induced by indirect costs rather than those induced by direct costs were found to be higher in ratio. In regard to each burden item, the results varied according to the characteristics of the farmers and their farm injuries. To support injured farmer, setting goals to reduce indirect cost burdens and preparing concrete methods is necessary.