• Title/Summary/Keyword: Quality of Concrete

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Application of the Pre-cast Concrete of the Super Flowing Concrete (초유동 콘크리트의 2차제품 적용에 관한 연구)

  • Kwon, Yeong-Ho;Lee, Sang-Soo;Won, Cheol;Park, Chil-Lim
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.285-291
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    • 1997
  • This study is the experimental results on the applicability of the super flowing concrete, which is the pre-cast concrete, to various cases. The primary purpose of this study is to verify the demolding strength, the handling strength of the super flowing concrete at various curing conditions, and the site quality control of the DWS (Daewoo Multi-Room Modular Construction System). From the experimental works, required strength and curing cycles are satisfied. Furthermore site quality control details and quality of the pre-cast concrete using the super flowing concrete are obtained. From now on, this study may suggest how to apply the super flowing concrete for common circumstance.

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A Study on the Characteristics of High-Quality Concrete Containing Silica Fume (실리카흄을 혼입한 고품질 콘크리트의 특성에 관한 연구)

  • 배수호;윤상대;박광수;신의균
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.88-93
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    • 1995
  • The purpose of this study is to investigate the mechanical properties and durability of high-quality concrete containing silica fume. For this purpose, the optimum quantity of silica fume were obtained for high-quality concrete, and the mechanical properties and durability of it are analyzed according to amount of combined material.

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Preperties of Foamed Concrete using Fly Ash for On-Dol (온돌 채움용 플라이애쉬 경량기포콘크리트의 품질 특성)

  • 고진수;임정수;전명훈;김종엽;손영준;이도헌
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.211-216
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    • 2000
  • Foamed concrete is applied ad filling, material of On-dol, bur it has much trouble in controlling the quality because of not establishing the detailed related criteria and recommendation for the construction and quality control practice. Therefore, this study will investigate the as-placed density and air content of formed slurry before hardening and its physical characteristics after hardening, analyzed the relation of each characteristic, and finally provide the proper method for the quality control foamed concrete.

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Mock-up Test of Exposed Concrete Wall using Self Compacting Concrete (노출 구조물 벽체에 적용하기 위한 무다짐 콘크리트 실물모형 실험)

  • 김규동;이승훈;손유신;김한준
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.561-566
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    • 2002
  • Recently, high quality exposed concrete is needed to achieve high quality surface for outer wall of the building. In this study, to solve above characteristic of the exposed concrete we selected self compacting concrete(SCC) and compared with normal concrete. So, we developed the SCC mix design and performed the semi mock-up test. Through this result, we performed the pilot test and mock-up test to check surface of outer wall and to measure formwork pressure As a result because SCC is better than normal concrete with respect to flowability and seggregation resistance SCC is suit to a exposed concrete needed high quality surface for outer wall of the building.

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Development of precast channel structure using polymer concrete (폴리머 콘크리트를 이용한 프리캐스트 수로구조물 개발)

  • 김관호;조태열;박광수;신수균;연규석
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.135-140
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    • 2001
  • This study was developed high-quality a large size precast channel structure using polymer concrete to improve quality of the product as well as to enhance construction quality. Precast PC represent the fastest growing segment of the polymer concrete industry. The fast curing, high strength, and low impermeability permit thin section and rapid reuse of moulds. Developed precast channel structure will be structural experiment and analysis. Also, through an example to construct will be develop the most suitable section survey and make practicable.

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Study for Korean Fly Ash Characterization (국내 플라이 애쉬의 품질특성에 관한 연구)

  • 강민호;하재담;김기수;차춘수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.95-98
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    • 1998
  • Fly ash is glassy dust collected from coal fired power plant. Recently, much research for fly ash conducted in Korea and fly ash is a valuable material especially when it used in high strength, high flowable, high durability concrete. But it varies with coal source, coal grinding and boiler conditions. Therefore, it is important that quality control of fly ash itself to get high quality concrete. In this study, over 20 samples of Poryong and Samchonpo fly ashs are tested and analyzed. The physical, chemical properties of fly ash and their relationships are investigated and it can be applied to quality control of concrete.

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Plans to Improve the Quality of Ready-Mixed Concrete and a Auggestion of Legislating a Concrete Engineer Certification (레미콘의 품질확보 방안 및 콘크리트 기사 자격제도)

  • 박승범
    • Magazine of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.14-21
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    • 2002
  • 국내에서 시공되는 콘크리트 구조물의 대부분은 레미콘(ready-mixed concrete)으로 시공되고 있기 때문에 레미콘의 품질관리(quality control) 및 품질확보(quality security)는 곧 콘크리트 구조물의 품질과 내구성의 확보를 위해 매우 중요한 사항이다. 최근 콘크리트 구조물의 잦은 사고로 인해 콘크리트의 품질문제가 사회문제로 나타나고 있으며 이에 대비한 콘크리트 품질보증 시스템의 확립이 시급한 실정이다. 그러나 레미콘의 품질환경은 원재료의 품질저하, 레미콘 운반시간의 증대 및 기술개발의 미흡 등 주변여건이 좋은 편은 아니며 레미콘 산업도 경쟁시대에 돌입하면서 레미콘 품질이나 기술우위의 시대로 변화되고 있다.(중략)

Improving the concrete quality and controlling corrosion of rebar embedded in concrete via the synthesis of titanium oxide and silica nanoparticles

  • Jundong Wu;Yan Cui
    • Advances in concrete construction
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    • v.15 no.1
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    • pp.1-10
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    • 2023
  • Concrete is one of the most widely used structure materials. Concrete is like the motor of the construction industry. The remarkable feature of this Concrete is its cheapness and low energy consumption. Concrete alone does not show resistance against any force but only against compressive forces. Therefore, steel rebar product is used as a reinforcement and increase the strength of Concrete. It can be done by putting rebar in Concrete in different ways. Rebar rusting is one of the crucial symptoms that cause swift destruction in reinforced structures-factors such as moisture in concrete increase the steel corrosion rate. In most cases, it is difficult to compensate for the damage caused by the corrosion of base metals, so preventing corrosion will be much more cost-effective. Coatings made with nanotechnology can protect Concrete against external degradation factors to prevent water and humidity from penetrating the Concrete and prevent rusting and corrosion of the rebar inside. It prevents water penetration and contamination into the Concrete and increases the Concrete's quality and structural efficiency. In this research, silica and titanium dioxide nanoparticle coatings have been used due to their suitable electrical and thermal properties, resistance to oxidation, corrosion, and wear to prevent the corrosion of rebars in Concrete. The results of this method show that these nanoparticles significantly improve the corrosion resistance of rebars.

A Study on the Properties of Concrete with the Variation of Addition Ratio of Expansive Additives (팽창재 혼입율 변화에 따른 콘크리트의 특성에 관한 연구)

  • 신언구;이대주;홍상희;전병채;한천구;반호용
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.229-234
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    • 1997
  • The objective of this study is to develop the non crack ready mixed concrete and the high quality concrete under various addition ratios of expansive additives. According to the experiment results, when expansive additive are mixed in concrete mixture by about 6% per cement contents, in W/B of 45~55%, it is found that the strength increase and the shrinkage compensation can be achieved by about 2~3 times. And it is considered to produce high quality concrete and non crack ready mixed concrete.

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A Study on the Quality Fluctuation of Hot Weather Concrete (하절기 콘크리트의 품질특성 변화에 관한 연구)

  • 김동석;정연식;유재상;김창범;이종열;김영준
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.665-668
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    • 2001
  • Generally, according to rising of atmospheric temperature, a consistency of concrete decreases, and a slump property of concrete is changed to be large. Also, in the strength development of concrete, the strength development rate of long-term age(28day) in comparison to strength of early age(7day) and the absolute compressive strength decreases. Accordingly, in this study, experiments about quality evaluation of concrete utilizing Ordinary Portland Cement is carried out. As a result of experiments, there were a conspicuous change in slump of concrete due to temperature increase. In conclusion, the rising of atmospheric temperature was very important factor in affecting the quality fluctuation of hot weather concrete.

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