• 제목/요약/키워드: construction quality grade

검색결과 77건 처리시간 0.029초

국내 골재 품질 현황 및 골재등급에 따른 콘크리트의 역학적 특성에 관한 연구 (Domestic Aggregate Quality Status and Mechanical Properties of Concrete According to Quality of Aggregate)

  • 민충식;박종호;정용;이재현;김용로;김효락
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.207-208
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    • 2012
  • This study is aimed to utilize for basic material of concrete quality management through evaluate properties of fresh and hardened concrete with the aggregate quality. As a result, fine aggregate's slump change of between one grade was 8~82% and in case of coarse aggregate, slump change of between one grade was 2~22% on same mixing condition. The unit water for same workability condition, unit water was increased 16kg/㎥ with decreasing of one grade for fine aggregate and unit water was increased 5kg/㎥ with decreasing of one grade for coarse aggregate.

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차량 D 단 소음의 음질 인덱스 및 등급화 구축 (Construction of the Sound Quality Index and Grade at Automotive Level D Noise)

  • 윤태건;박상길;심현진;이정윤;오재응
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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    • pp.186-189
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    • 2005
  • Since human listening is very sensitive to sound, a subjective index of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. Many researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. In this study a reliable index is constructed and analyzed using correlation analysis, regression analysis and weighting factor for each sound quality factor. We have made the sound quality index that agrees with more than human subjective sensitivity which apply to various sound quality metrics. Also we applied a 'grade' metric to jury for sound evaluation, analyzed relation between sound duality index and sound quality grade. Then we will judge the sound quality level according to the sound quality grade scheme.

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저속습식마쇄기를 이용한 고품질 순환잔골재 제조에 관한 기초적 연구 (A Fundamental Study on Manufacturing Condition the High Quality Recycled Fine Aggregate by Low Speed Wet Rotary Mill)

  • 김하석;이경현;라정민;박효진;임대빈;김진만
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 추계 학술논문 발표대회
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    • pp.65-68
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    • 2009
  • Recycled aggregate by the recycling construction waste has a lot of advantage such as the developing the alternative resource and protecting of environment. However, recycled aggregate is used as the low quality grade, because the technic to remove old mortar from aggregate is low level. To use the recycled aggregate as high quality grade, it is important to develop the technic to produce the high quality recycled aggregate. To manufacture the high quality recycled aggregate, old mortar attached on the aggregates should remove efficiently. Therefore, in this study, we suggested the optimum condition to remove old mortar effectively using sulfuric acid and low speed wet rotary mill for high quality recycled fine aggregate. The results shows that the recycled aggregate satisfy on the standards of KS F 2573 in density, absorption and solid volume when, adequate condition of sulfuric mole ratio and aggregate ratio are make.

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초급 건설사업관리기술자(CMr)의 요구역량 추출 및 ANP 중요도 분석 (An Extraction and ANP Importance Analysis for Competence Factors of Junior Grade CM Engineer)

  • 양진국;김세범;이상범
    • 한국건설관리학회논문집
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    • 제18권1호
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    • pp.58-64
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    • 2017
  • 건설관리 (CM)는 효율적인 프로젝트 관리 시스템으로서 활용되고 있다. 건설관리 시스템은 과학적 관리 기법을 제공할 뿐만 아니라, 전문 지식을 가진 전문가의 서비스를 제공한다. 따라서 CM 서비스 수요는 건설 프로젝트에서 지속적으로 증가하고 있다. 건설사업관리기술자의 등급은 건설 기술자 역량지수 (ICEC)에 의해 구분된다. 건설사업관리기술자는 다른 분야보다 높은 점수를 필요로 한다. 하지만 초급 건설사업관리기술자는 교육과 자격에 따라 등급을 획득할 수 있다. 본 연구는 현행 건설사업관리기술자 등급 시스템의 문제점을 분석한 후 초급 건설사업관리기술자를 대상으로 인터뷰를 실시하였다. 그 결과 본 연구에서는 23가지의 요구역량 요인들을 추출하였다. 그리고 요구역량은 친화도법을 사용하여 5가지 영역으로 그룹화 하였다. 다음으로, ANP 기법을 이용하여 중요도를 분석하였다. 그 결과 우선 순위가 높은 영역이 프로젝트 관리와 관련된 품질 및 비용 영역으로 분석되었다.

습식 중화반응에 의한 순환 잔골재의 품질 향상 (Quality Improvement of Recycled Fine Aggregate by Neutralization Reaction in Water)

  • 김하석;김진만;선정수;배기선
    • 한국건설순환자원학회논문집
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    • 제3권2호
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    • pp.146-151
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    • 2015
  • 순환골재는 건설폐기물을 재활용함으로써 자원절약 및 대체자원의 개발과 환경보호의 측면에서 국가 사회적으로 많은 이점을 가지고 있다. 하지만 낮은 밀도와 높은 흡수율을 가지는 저품질 순환골재는 구조용 콘크리트 골재로 사용되지 못하고 주로 저부가가치로 사용되고 있다. 고품질 순환골재를 생산하기 위해서는 골재와 골재에 부착된 구모르타르를 효과적으로 제거해야 한다. 최근 물리적 화학적 방법을 이용하여 구모르타르를 효율적으로 제거하기 위한 연구가 행해지고 있으나, 고품질 순환잔골재의 생산 조건에 관한 정량적 연구는 아직 부족한 실정이다. 따라서 본 연구에서는 고품질 순환잔골재를 생산하기 위해서 황산과 저속습식마쇄기를 이용하여 구모르타르를 효과적으로 제거할 수 있는 최적 조건을 제시하고자 하였다. 황산의 몰비와 골재비율에 따른 순환골재의 실험결과 밀도, 흡수율, 실적율은 기준을 만족시키는 결과를 나타내고 있는 것을 알 수 있었다.

확률분포를 이용한 남한강 보 건설 전·후 수질변화 분석 (Analysis of Water-Quality Constituents Variations before and after Weir Construction in South Han River using Probability Distribution)

  • 김경섭
    • 한국물환경학회지
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    • 제35권1호
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    • pp.55-63
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    • 2019
  • The Four Major Rivers Restoration Project started in 2009 and completed in early 2013 is a large-scale inter-ministry SOC project investing ₩22.2 $10^{12}$ and one of the Project's objectives was to enhance the water-quality grade through recovering the river eco-system and environment. The average concentration and probability distribution of water-quality constituents at given and selected sampling sites are very significant elements for analyzing and controlling the water-quality of rivers or reservoirs effectively. Average concentration can be estimated by point estimator, distribution function of water-quality constituents or Bootstrap method, in which the distribution function estimated with more data in case of insufficient dataset, is applied. Ipo and Gangcheon water-quality monitoring stations in South Han River were selected to compare and analyze the variation of concentration before and after Ipo and Gangcheon Weirs construction, using the whole 4-year's data, from 2005 to 2008 and from 2014 to 2017. Water-quality constituents such as BOD and COD relating to oxygen demanding wastes and TP and Chlorophyll-a relating to the process of nutrient enrichment called eutrophication were also selected. The guidelines for water-quality control and management after weir construction including evaluation of water-quality constituents' variations can be presented by this paper.

자착식형 방수 시트의 평가 항목별 성능등급 제안에 관한 연구 (A Research on Suggestion of Performance Grade for each Assessment Items of Self-Adhesive Waterproofing Sheet)

  • 박완구;안기원;허능회;김윤호;박진상;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.23-25
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    • 2012
  • Because Self-Adhesive Waterproofing sheet has good constructability, it has been widely used. Also Self-Adhesive Waterproofing sheet is researched based on variety of materials and various of forms. However, producers have recognized about only pass KS quality standard. So, Self-Adhesive waterproofing sheet has been limited about improvement of performance. Therefore, in this research, proposed guideline of Self-Adhesive Waterproofing sheet for disinterested performance grade using probability theory and quality management theory.

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공동주택 건축마감자재 오염물질 방출에 관한 연구 (A Study of Pollutants emitted from Apartment finishing Materials)

  • 김민우;이충근;황동규;이성연
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.981-985
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    • 2008
  • Construction company's role is getting bigger recently because of interest of indoor air quality problem. The using environment-friendly building finishing material is the most benefit method to reduce pollutants in house. It is confirmed the actual condition of environment-friendly building finishing material such as wallpapers, wooden flooring boards, glues, paints, adhesives, plaster boards that are used the work of apartment construction in 2006-2007. It shows that environment-friendly materials have excellent grade mostly, general materials have pass I, pass II grade mostly and are high TVOC emission.

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낙동강 지류 이안천의 수질 평가 (Estimation on the Water Quality of the Ian Stream, a Tributary of the Nakdong River)

  • 최광순;이혜근;김호준;김세원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.1239-1243
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    • 2005
  • The water quality of the Ian Stream, a tributary of the Na14dong River, was estimated to provide an information in establishment of an ecological restoration plan for fan dam which will be constructed in near future. Seven stations were selected in upstream (3 stations) and downstream (4 stations) of Ian Stream, centering the construction site of Ian dam. Samples were collected at the surface water of 7 stations selected on May 1, June 16, and September 1 in 2004. The values of DO, pH, and BOD are satisfied Grade I for river water standard in nearly all sites. The concentrations of total nitrogen (TN) and total Phosphorus (TP) showed low level with ranges of $1.10\~2.25\;mgN/L,\;5\~14\;{\mu}gP/L$. However, the total and fecal conform bacteria were detected in nearly stations, especially high at the upstream stations. The number of fecal conform bacteria corresponds to the Grade III for river water standard. In addition, some metals (iron, manganese) were detected during dry season. As a consequence, general water quality of Ian Stream satisfied Grade I for river standard and it is expected that pollution loads from watershed is not significant. However, the detection of fecal conform, which is thought to be from livestock and residents, and some metals originating mimes watershed can have a potential health risk exists for aquatic organisms lived in Ian Stream. It needs to be solved by the construction of wastewater treatment plant to diminish the health risk from stream water polluted by fecal conform and metals, and to provide the safe ecological habitat for aquatic organisms.

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공동주택 성능등급 표시제도 강화를 위한 방수성능 등급 도입에 관한 연구 (Study on the Improvement of Waterproofing Performance Rating for the Introduction of Residential Apartment Complex Performance Grade Index)

  • 안기원;조일규;오상근
    • 대한건축학회논문집:구조계
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    • 제34권12호
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    • pp.41-49
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    • 2018
  • The current housing performance rating system displays the performance rating of the houses supplied by the housing construction company, approved by the Housing Law. This system is intended to provide accurate information to the consumers in the announcement of the tenant recruitment, thereby improving the quality of the housing. This system was revised in January 2005 and implemented from January 2006. It is obligatory for companies with a scale of more than 1,000 households (energy performance rating is over 300 households), but there is currently no content on the waterproofing field. Therefore, this study suggests the revision plan proposes the necessity of the inclusion of the performance grade for the waterproofing field which is not currently implemented in the apartment house performance rating system, and to understand how to secure an adequate living environment. As a result, according to survey results, the performance score based on the difficulty of the maintenance method according to future leaks was selected and the revised system was prepared. Based on this, the performance grade for the virtual apartment was evaluated, and the results show that the performance of various grades is presented accordingly.