• 제목/요약/키워드: Lightweight concrete

검색결과 621건 처리시간 0.023초

Bond behavior of PP fiber-reinforced cinder concrete after fire exposure

  • Cai, Bin;Wu, Ansheng;Fu, Feng
    • Computers and Concrete
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    • 제26권2호
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    • pp.115-125
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    • 2020
  • To reduce the damage of concrete in fire, a new type of lightweight cinder aggregate concrete was developed due to the excellent fire resistance of cinder. To further enhance its fire resistance, Polypropylene (PP) Fibers which can enhance the fire resistance of concrete were also used in this type of concrete. However, the bond behavior of this new type of concrete after fire exposure is still unknown. To investigate its bond behavior, 185 specimens were heated up to 22, 200, 400, 600 or 800℃ for 2 h duration respectively, which is followed by subsequent compressive and tensile tests at room temperature. The concrete-rebar bond strength of C30 PP fiber-reinforced cinder concrete was subsequently investigated through pull-out tests after fire exposure. The microstructures of the PP fiber-reinforced cinder concrete and the status of the PP fibre at different temperature were inspected using an advanced scanning electron microscopy, aiming to understand the mechanism of the bonding deterioration under high temperature. The effects of rebar diameter and bond length on the bond strength of PP fiber-reinforced cinder concrete were investigated based on the test results. The bond-slip relation of PP fiber-reinforced cinder concrete after exposure at different temperature was derived based on the test results.

콘크리트 슬러지를 이용한 인공골재 의 품질특성 (The Quality Characteristics of Artificial Aggregate using Concrete Sludge)

  • 고대형;이정재;문경주;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.269-274
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    • 2001
  • The purpose of this study is to evaluate basic properties of artificial aggregate using concrete sludge according to mixing ratio. Cement, waste phosphogypsum and Powder of blast furnace slag are used with binder of artificial aggregate. Specific gravity, absorption are tested for basic property, and impacting, abrasion and crushing tests are done for characteristics of strength on the aggregate, including comparison with crushed stone. Bry specific gravity was ranged about 1.16 to 1.30 the test result of the aggregates and shape is round In the result of tests, it is concluded that qualities of the aggregates using concrete sludge are slightly lower than crushed stone but it is similiar with sintering artificial lightweight aggregate in high temperature.

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석탄회 및 폐플라스틱을 이용한 인공경량합성골재의 개발 (Development of lightweight Fly ash-Plastic Aggregate)

  • 조병완;박승국;박종빈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.380-383
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    • 2004
  • The coarse and fine aggregates that make up the majority of concrete are resources. But, the raw naturals that make up concrete are our earth's resources and there is not a replenishable stock. Also industrial waste and life waste leaped into a pollution source. Therefore, as construction continue, quarries are exhausted and new sources must be discovered. The purpose of this paper is to investigate an application of recycled coal ash plastics in the construction field. The study examined the physical and mechanical properties of recycled coal ash plastics aggregate. In the results, although the absorption and specific gravity of SLAs increases slightly as the fly ash content increases, the compressive strength and modulus of elastic of concrete made with SLAs remains relatively constant when mortar type and volume fraction are also held constant. These values are always lower than natural-weight aggregate concretes.

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산업부산물을 활용한 고강도경량 콘크리트 건조수축 특성연구 (A Study on shrinkage of High Strength Lightweight Concrete using by-products)

  • 장주영;윤요현;이승조;박정민;김태곤;김화중
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.36-39
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    • 2003
  • In this study, we made the high strength light weight concrete which was composed of the garnet minute powder to be the industry by-product in the YoungJoo region and the artificial light weight aggregate which the high temperature(1100℃) plastic process. The characteristic of the autogenous shrinkage had been considered about strength characteristic and the age passage In the following addition: The concrete's each unit quantity was determined 145,160,175㎏f/㎥.w/b and s/a was determined 30%, 43%, 45%. the each garnet's substitution ratio was determined 0, 10%. In this results, the compressive strength appeared greatly as the unit joining discretion grew bigger. The autogenous shrinkage ratio was increased rapidly until 7th day but it was reduced after 7th day regardless of the mixed factor. The autogenous shrinkage ratio which follows the change of the unit quantity and s/a increased together as the unit quantity and the s/a increases.

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비정형 콘크리트 패널 생산 시스템 구축 기초연구 (A Basic Study of Production System Development of Free-form Concrete Panels)

  • 손승현;김기호;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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    • pp.70-71
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    • 2019
  • Glass fiber reinforced concrete (GFRC) is very suitable as a material for free-form concrete panels (FCPs) because of its lightweight, strong, moldable, durable and sustainable properties. GFRC is superior in construction and maintenance compared with materials such as steel, aluminium, titanium, glass and plastic, and is advantageous in cost. However, GFRC is being produced by skilled craftsmen, and still lacks the technology to economically produce high quality FCPs. Currently, there is a technology to automatically and accurately produce FCPs. However, the developed technology can not be applied to the field with simple production technology without production line for mass production. To solve this problem, the purpose of this study is a basic study of production system development of free-form concrete panels. This study introduces the developed FCPs production technology and builds FCP production system for mass production. The results of this study will be used as basic data for the commercial production of FCPs in the future.

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단열성능 향상 콘크리트의 현장 적용성 평가에 관한 연구 (Study on the Field Application of Insulation Performance Improvement Concrete)

  • 강성혁;김정호;추경남;박영신
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.17-18
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    • 2014
  • Recently, climate change have increased consumption of building heating and cooling energy. Therefore, various actions to reduce greenhouse gas and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. Especially the outer covering of the building has been made of concrete more than 70%. But a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using Micro Form Admixture and Calcined Diatomite Powder and Lightweight Aggregate.

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CKD 치환율 변화에 따른 경량기포 콘크리트의 특성 (Properties of Lightweight Foamed Concrete with Incorporating Ratio of Cement Kiln Dust)

  • 신현섭;신재경;정광복;배장춘;김성수;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.861-864
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    • 2006
  • This study investigates the properties of light weight foamed concrete with variances in incorporating ratio of cement kiln dust(CKD). Test showed that an increase of CKD incorporating ratio decreased the fluidity of fresh concrete and increased the unit weight. A sinking depth of specimens incorporating CKD decreased, compared with that of control. As for the compressive strength, it firstly increased and then slightly decreased when incorporated CKD. Tensile strength values were similar to the values of compressive strength, but the ratio of comp. to tens. strength increased. Appearances density of specimens were all raged in KS and the thermal conductivity was also satisfied in KS; less than 0.05-0.160W/($m{\cdot}k$).

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국내 경량골재콘크리트 관련 규격의 현황 및 문제점 분석 연구 (A Study on the Present States & Problems of Domestic Standards for Lightweight Aggregate Concrete)

  • 김상헌;박대오;지석원;유택동;최수경;서치호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.405-408
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    • 2006
  • In this study it compares a Japanese standards which is most similar contents with domestic standards related with the light weight aggregate concrete and derives the fundamental data from the results so that it will be able to refer at maintenance of standards or specifications in future. The case of domestic is the actual more insufficient condition which is described in the standards and the specifications than Japanese standards. For the production of he domestic light weight concrete the development of general standards and construction guides and control of water content ratio of the light weight aggregates become accomplished rightly in quality of construction site.

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