• Title/Summary/Keyword: Mat building

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Experimental Study on Field Applicability of Tightened Coupler with Two-Way Threading (양방향 나사산 체결방식을 활용한 완전밀착형 커플러의 시공성 분석)

  • Park, U-Yeol;Hong, Seong-Wook;Yang, Jin-Kook;Ko, Suck-Hwa;An, Sung-Hoon
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.1
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    • pp.87-93
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    • 2014
  • A tightened coupler with two way-threading is suggested to overcome the previous one-way threaded coupler. The experiment and a mock-up test were conducted to analyze the constructability of the suggested coupler. The aim of the mock-up test was to assemble the suggested coupler in horizontal rebar of mat footing and vertical rebar of semi-fabricated column bars. The method using the suggested coupler in semi-fabricated column bars is developed by analyzing the problem of fabricated column bars using the one-way threaded coupler. The result of the mock-up test showed that the time required to assemble the suggested coupler in the horizontal bars is shorter than it is for the one-way threaded coupler. In addition, the method using the suggested coupler in semi-fabricated column bars has advantages such as lower working loads, supporting safe work and strongly tightening the rebar. From these results, it is revealed that the suggested coupler is adequate to use in rebar work in terms of cost, quality and time.

Field Application on Mass Concrete of Combined Coarse Particle Cement and Fly-Ash in Mat Foundation (조분(粗粉) 시멘트와 플라이애시를 복합 치환한 매트 기초 매스콘크리트의 현장적용)

  • Han, Cheon-Goo;Jang, Duk-Bae;Lee, Chung-Sub
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.4
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    • pp.11-20
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    • 2010
  • This study carried out a Mock-up test to apply Low-heat Cement (CF) that is adjusted to a fineness of $3,000\;{\pm}\;200\;cm^2/g$ by substituting Coarse particle Cement (CC) and fly ash with ordinary Portland Cement (OPC), then applied it on-site. The result of the test is as follows. The Mock-up test showed that the amount of admixture in CF increased SP agent and AE agent slightly more compared to OPC, while temperature history showed that the highest temperature of CF was around $6{\sim}10^{\circ}C$ lower than that of OPC. Compressive strength in CF was low compared to that of OPC, but the strength width became narrow at the age of 28 days, which is not considered to be significant. In on-site application, slump, air content and chloride content all satisfied the target values, while the temperature history showed that the highest temperature in the center by each cast was about $34^{\circ}C$ in the first cast, $42^{\circ}C$ in the second cast, and $39^{\circ}C$ in the third cast. Compressive strength of specimen for strut management showed low value compared to standard curing, but its strength was reduced at the age of 28 days.

A Study on the Basic Planning of the Nam-Hae Sin-Sa Architecture (남해신사 기본계획에 따른 신당건축 고찰)

  • Kim, Sang Tae;Jang, Hun Duc
    • Korean Journal of Heritage: History & Science
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    • v.42 no.2
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    • pp.62-85
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    • 2009
  • The Nam-Hae Sin-sa, the South Sea shrine in Yeong-Am, Korea was a national institution for public peace and bliss, was excavated in 2000, and the shrine and the 3-way-gate were reconstructed in 2001. Hae Sin-sa, the Sea shrine is a place for religious service separated into the Nam-Hae Sin-sa, the Dong-Hae Myo, and the Seo-Hae Dan. The Dong-Hae Myo was reconstructed, but restored shrine and 3-way-gate of the Nam-Hae Sin-sa is not perfect in comparison with excavation plan in 2000, therefore new reconstruction was researched through the related literature, the analysis of historical maps and excavation results, the interview with the concerned people and the case study. This research defines the analysis of the Plan of the Nam-Hae Sin-sa Reconstruction as follows. 1. The Nam-Hae Sin-sa was the institution for religious service operated by national direct management, represents the shrine for public peace and bliss on the Mountain, the Sea, and the River. Especially the Nam-Hae Sin-sa had an important position on the pivot of international trade with China and Japan, and had a role of main shrine with another one in the Mt. Ji-ri San. 2. The name of the Sea shrine was called as Nam-Hae Sin-sa(the South Sea shrine), Dong-Hae Myo(the East Sea shrine), Seo-Hae Dan(the West Sea shrine). But the name of the South Sea shrine had changed in the early period of Chosun as Nam-Hae Sin-sa to the later Chosun as Nam-Hae Dang through the research of related literature and historical map. Such as the Seo-Hae Dan, it was constructed for the Dan, the flat raised-floor without buildings, and changed to the type of Sa-Dang with addition of buildings. 3. The historical map of Hae Sin-sa informs the types of the roof, the Mat-bae roof was used in the Dong-Hae Myo, but the Pal-jak roof was showed in the Seo-Hae Dan and the Nam-Hae Sin-sa. 4. According to the analysis of Yong-Ch'uck the unit length, Nam-Hae Sin-sa was reconstructed in the period of Koryo on large scale, but it was restored in the Chosun on middle scale. And the Unit of Yong Ch'uck was changed into Yeong-jo Ch'uck in the period of Chosun. 5. As the results, The Plan of the Nam-Hae Sin-sa Reconstruction designed the new shrine into the 3 Kan front and the 2 Kan side with 3:2 scale. An-ch'o-gong with Yong-du and Yong Mi the ornaments represents head and tail of dragon, the Un-gong and the ornament of Pa-ryun-dae-gong in the building, and the Ch'ung-ryang of the Yong-du show the image of the institution for religious service for the god of the sea who look like dragon. The inner gate building and the main entrance were designed as same plan and scale as Hyang-gyo, the Korean Traditional School and Shrine of Confucianism, on the basis of results of excavation. Raise the 3-tall gate of the main entrance with harmony of the scale and the shape, because the side of gate building has the Mat-bae roof. 6. This research shows that Plan of the Nam-Hae Sin-sa Reconstruction is composed into shrine space and reservation space from the main entrance to inner gate and shrine like Jung-ak Dan in the Mt. Gye-ryong San, and it also informs the well in the west side of Sin-sa is an important factor of the plan of shrine architecture.

A Case study and Analysis on the Up-Lift Pressure Treatment Evaluation of Underground Installations for their Efficient Adoption (사례분석을 통한 효율적 상향수압(Up-Lift Pressure) 처리공법 적용방안에 관한연구 - ◯◯ 상업지역 현장사례 중심으로 -)

  • Ko, Ok-Yeol;Kwon, Oh-Chul;Shim, Jae-Kwang;Park, Tae-Eun
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.119-129
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    • 2009
  • Building construction trends have been changed dramatically in terms of size and mass. With the need to maximize land usage, there has been an increase in the construction of high-rise buildings. This affects not only the entire construction duration and cost, but also subsequent construction activities, such as work to increase underground facilities and in reclamation land area construction. These types of site conditions require soft ground reinforcement and the proper uplift water pressure treatment. In general, two kinds of methods have been used for uplift water pressure treatment systems. However, there have been some problems arising as the result of a lack of research and analysis on underground construction techniques, and a reliance on experiments over actual survey and analysis of site conditions. This paper focused on the problems of conventional selection procedure, by analyzing drawings and proposing a kind of modeling for a reasonable procedure. The results were applied to OO project as a sample construction case to be verified in this research. The initial plan in the case project was the Rock Anchor System. However, as there were terrible miscalculations of basic site conditions that had an extraordinary influence on the underground water level, such as the site's proximity to the Han-river, it was necessary to change the plan to include apermanent drainage system. This achieved a direct construction cost reduction \ 406,702,000 and a maximum sayings of 4% of operational cost, based on the 50-year building Life Cycle Cost.

Effect of Organic Matter Ratios in Substrate and Mulching Materials on Growth of Liatris spicata under Non-irrigated Green Roofs (무관수 옥상녹화에서 유기질 비료와 멀칭재에 따른 리아트리스(Liatris spicata) 생육 반응)

  • Ju, Jin-Hee;Yoon, Yong-Han
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.130-137
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    • 2012
  • This research evaluated the effectiveness of organic matter ratios in substrate and mulching materials under mn-irrigated condition green roofs by measuring the effects on growth of Liatris spicata. Four mulching materials were installed, i. e. nun-mulched control(CON), volcanic ash soils(VAS), non-woven black fabric mat(NBM) and pine bark(PAK). Three levels of organic maller volume percentage in an amended soil were evaluated, amended soil: organic matter=100:0($A_1O_0$), amended soil: organic matter=80:20($A_4O_1$) and amended soil: organic matter=50:50($A_1O_1$). Plant height, number of leaves, diameter of flower stalk, number of florets, chlorophyll contents, shoot fresh and dry weight were recorded from April to September, 2010, and survival rate was examined on May 2011 of the following year. In the $A_1O_0$, the number of leaves, number of florets and chlorophyll contents were higher in Liatris spicata grown on NBM than other mulching treatments. Especially, plant height, shoot fresh and dry weight were significantly higher. However, it resulted the lowest survival rate than other mulching treatments. 2. In the $A_4O_1$, the plant height, number of leaves, number of florets, shoot fresh and dry weight were higher than other mulching treatments, but there was no significant difference except for the plant height of Liatris spicata grown on NBM. The survival rate was decreased by 40~60%, compared with $A_1O_0$, after overwintering. 3. In the $A_1O_1$, the plant height, number of leaves, diameter of flower stalk, number of florets, chlorophyll contents, shoot fresh and dry weight were slightly higher than other mulching treatments, but there was no significant difference from Liatris spicata grown on NBM and VAS. The survival rate was observed by 0% over all mulching treatments after overwintering. Therefore, the non-woven black fabric mat(NBM) promoted the Liatris spicata's growth and flowering compared with other mulching treatments. However, the survival rate was decreased significantly, and the organic matter ratios were increased after overwintering under non-irrigated green roofs.

An Experimental Study on Properties of Concrete Using Latent Heat Binder (잠열성 결합재를 활용한 콘크리트의 특성에 관한 실험적 연구)

  • Kim, Yong-Ro;Kim, Do-Su;Khil, Bae-Su;Kim, Ook-Jong;Lee, Do-Bum
    • Journal of the Korea Concrete Institute
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    • v.20 no.5
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    • pp.661-668
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    • 2008
  • It is necessary to develop a new technology for effectively reducing hydration heat and controlling thermal cracking caused increasing construction of large size massive concrete structures such as mat foundation of high-rise building, grandiose bridge, and LNG tank. Therefor, to develop a new technology for reducing hydration heat of large size massive concrete in this study, after developing the latent heat binder for controling hydration heat of concrete by application of latent heat material, it was investigated basic properties and durability such as slump, air content and compressive strength, shrinkage properties, permeability, freezing and thawing resistance, corrosion, and hydration heat generation properties of concrete using latent heat binder. As a test result, it was confirmed that latent heat binder was not affected adversely the basic property and durability of concrete, and was advanced on the reduction of hydration heat and control of thermal crack. It is expected to be applied as the excellent technology on the management of hydration heat and thermal crack in large size mass concrete structures.

Mock-up Test of Improving Super Retarding Concrete to Control of Hydration Heat Crack of Foundation Mat Mass Concrete (기초매트 매스콘크리트의 수화열 균열제어로서 초지연콘크리트 활용에 관한 Mock-up 실험)

  • Lee, Jae-Sam;Bae, Yeoun-Ki;Noh, Sang-Kyun;Kim, Suk-Il;Chung, Sung-Jin;Han, Cheon-Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.777-780
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    • 2008
  • According to the recent tendency that the buildings in the downtown are gradually Manhattanized, the very thick massive concrete is selected as the foundation of architectures. By the way, because this mass concrete cannot be simultaneously pour in a great quantity due to the circumstance at the field, not only the questions on the unification between the concretes pour on the upper layer and the lower layer are presented but also the cracks by the internal force from the difference of hydration exothermic period are occurred, which are pointed out as the problems. Thus, this study performed Mock-up test to apply the hydration heat controlling method of massive concrete for horizontal partition pouring construction to the building sites for the purpose of securing the stability on the cracks by the internal force from the difference of hydration exothermic period on the upper layer and the lower layer of massive concrete and checked the efficiency. As the results of test, in case of setting time difference method by super retarder with 2 layers and 4 layers, the effect that temperature gaps between upper part and lower part were lowered and the possibility of crack occurrence was decreased as the peak time of the heat of hydration became delayed to the latter term could be confirmed.

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A Study on Manufactural Condition of Vegetation Mat for Greening Impermeable Surfaces Using Wood Waste (폐목질 자원을 이용한 인공지반 녹화용 식생기반재의 제조조건에 관한 연구)

  • Kim, Dae-Young;Kim, Mi-Mi
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.3
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    • pp.165-169
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    • 2010
  • The cityward tendency of the population caused the building crowd and the skyscrapers, and destroyed the cityscape and ecosystem of the city. For this reason, many researchers studied to make more green spaces in the city. The roof greening is one of the methods to get the green spaces in the city. There are some problems in this method such as the safety load, growth of the plants on the artificial foundation, and so on. In this study, we evaluated the waste woodchips and the waste papers as a new materials for the artificial foundation. The new artificial foundation was made of the waste woodchips and the waste papers with the different ratio of mixture (woodchips, paper slurry, and fertilizer). The artificial foundation was applied to the planting of three different plants (creeping bentgrass, barley, and wheat). It was found that the growth of the plants with 1% of fertilizer was higher than other conditions. The best making condition of foundation was 40% pulp and 60% woodchips in the germination of all plants.

Management of plant genetic resources at RDA in line with Nagoya Protocol

  • Yoon, Moon-Sup;Na, Young-Wang;Ko, Ho-Cheol;Lee, Sun-Young;Ma, Kyung-Ho;Baek, Hyung-Jin;Lee, Su-Kyeung;Lee, Sok-Young
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.51-52
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    • 2017
  • "Plant genetic resources for food and agriculture" means any genetic material of plant origin of actual or potential value for food and agriculture. "Genetic material" means any material of plant origin, including reproductive and vegetative propagating material, containing functional units of heredity. (Internal Treaty on Plant Genetic Resources for Food and Agriculture, ITPGRFA). The "Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) to the Convention on Biological Diversity (shortly Nagoya Protocol)" is a supplementary agreement to the Convention on Biological Diversity. It provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD: the fair and equitable sharing of benefits arising out of the utilization of genetic resources. The Nagoya Protocol on ABS was adopted on 29 October 2010 in Nagoya, Japan and entered into force on 12 October 2014, 90 days after the deposit of the fiftieth instrument of ratification. Its objective is the fair and equitable sharing of benefits arising from the utilization of genetic resources, thereby contributing to the conservation and sustainable use of biodiversity. The Nagoya Protocol will create greater legal certainty and transparency for both providers and users of genetic resources by; (a) Establishing more predictable conditions for access to genetic resources and (b) Helping to ensure benefit-sharing when genetic resources leave the country providing the genetic resources. By helping to ensure benefit-sharing, the Nagoya Protocol creates incentives to conserve and sustainably use genetic resources, and therefore enhances the contribution of biodiversity to development and human well-being. The Nagoya Protocol's success will require effective implementation at the domestic level. A range of tools and mechanisms provided by the Nagoya Protocol will assist contracting Parties including; (a) Establishing national focal points (NFPs) and competent national authorities (CNAs) to serve as contact points for information, grant access or cooperate on issues of compliance, (b) An Access and Benefit-sharing Clearing-House to share information, such as domestic regulatory ABS requirements or information on NFPs and CNAs, (c) Capacity-building to support key aspects of implementation. Based on a country's self-assessment of national needs and priorities, this can include capacity to develop domestic ABS legislation to implement the Nagoya Protocol, to negotiate MAT and to develop in-country research capability and institutions, (d) Awareness-raising, (e) Technology Transfer, (f) Targeted financial support for capacity-building and development initiatives through the Nagoya Protocol's financial mechanism, the Global Environment Facility (GEF) (Nagoya Protocol). The Rural Development Administration (RDA) leading to conduct management agricultural genetic resources following the 'ACT ON THE PRESERVATION, MANAGEMENT AND USE OF AGRO-FISHERY BIO-RESOURCES' established on 2007. According to $2^{nd}$ clause of Article 14 (Designation, Operation, etc. of Agencies Responsible for Agro-Fishery Bioresources) of the act, the duties endowed are, (a) Matters concerning securing, preservation, management, and use of agro-fishery bioresources; (b) Establishment of an integrated information system for agro-fishery bioresources; (c) Matters concerning medium and long-term preservation of, and research on, agro-fishery bioresources; (d) Matters concerning international cooperation for agro-fishery bioresources and other relevant matters. As the result the RDA manage about 246,000 accessions of plant genetic resources under the national management system at the end of 2016.

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