• Title/Summary/Keyword: Quality of Concrete

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Quality Management of Exposed Concrete at Construction Phase (시공단계 노출 콘크리트 품질관리 방안)

  • Kim, Tae-Hoon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.164-165
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    • 2016
  • To express the original texture of the concrete, exposed concrete finishing technique has been applied in many buildings. However, it is likely to cause quality problems after construction is completed. In addition, because of costs and time issues, reconstruction and maintenance works are difficult and ineffective. Therefore, step-by-step proactive quality management based on sufficient consensus among participants(client, designer, contractor) is very importatnt. This study analyzed factors causing low quality exposed concrete and quality contol points applied to 'A' headquarter construction project.

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The Properties of Sea Sand with Digging Sources (산지별 세척사 특성)

  • Kim, Jung-Bin
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.2 no.2
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    • pp.76-82
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    • 2006
  • High-strength, High-durability concrete appearance was embossed by benevolence who quality for each raw material that become factor that is direct in concrete manufacture and the special quality is very important and request properties of matter were also strengthened more. Specially, natural resources of good quality were abundant past in occasion of aggregate and unlike concrete request strength past that the importance was less relatively the quality enemy than cement because is also not big, importance of aggregate quality great veried as concrete strength and request properties of matter about durability are strengthened more on extreme displacement. Mixing four who is original and mixs special quality examination of domestic three Four-Stick Games by Chaechwiwon and age Four-Stick Games and crushed sand examined concrete quality characteristic that use mortar and concrete quality characteristic, special quality of North Korea sun guardian mountain three Four-Stick Games that is imported from the North Korea, North Korea sun guardian mountain three Four-Stick Games etc..

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A Study on the Quality of Concrete Place under Raining Condition (우기중에 타설된 콘크리트의 품질 특성에 관한 연구)

  • 권영웅;정성철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.729-736
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    • 1997
  • This paper gives the information of field concrete placed under raining condition. Experimental factors in this study are concrete strength, standard deviation and coefficient of variation. The results are as follows: 1. The strength of field concrete placed under raining condition is not largely dependent on the raining condition. 2. But, the quality of concrete is very critical.

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Development of Early Evaluation System for Concrete Quality, Construction and Maintenance (콘크리트 품질ㆍ시공ㆍ유지관리의 조기판정시스템 개발)

  • 손용우;이증빈;최미라;박봉수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.517-526
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    • 2004
  • In the resent years, the early evaluation of concrete quality, construction and maintenance has been considered as all is of major concern due to the increase of loading and the degradation of structures related with time. This paper presents evaluation of structural safety performance using measured data of construction, on the basis of a field measurements for the prevention of unreliable concrete works. Measurements analyzed in this paper are early quality condition and performance assessment, serviceability performance by cracks and deflection, rating performance by loading, durability performance by chloride attack and carbonation. Thus, a quantitative assessment model of resistance capacity was developed here to meet the requirement for deteriorated concrete structures. The model focuses on damage mechanical of concrete structures deteriorated by initial damage factors for concrete quality and environment factors such as chloride and carbonation attacks. These results could provide useful information for concrete structures interested in design, construction and maintenance.

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An Experimental Study on Quality Control Standards of Exposed Concrete in Construction Stage (노출콘크리트 시공단계 품질관리 기준에 관한 실험연구)

  • Jeong, Jae-Soo;Lee, Chan-Sik
    • Korean Journal of Construction Engineering and Management
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    • v.13 no.2
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    • pp.48-57
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    • 2012
  • A variety of studies on concrete have been performed to examine the advantages for structural material, but less attention has been paid to the contribution of concrete to finishing. Due to this matter, specific management guidelines for construction and quality on exposed concrete have not been clearly established despite more construction cost and quality control are required. This study analyzed a impact factors on the quality by survey of the existing research and practice. Field tests were performed using mock-up models to analyze the quality of exposed concrete according to form manufacture method, concrete mix proportion, and concrete placing method. Results indicate that the quality of exposed concrete was determined by concrete mix proportion and construction managements. Guidelines of quality control on exposed concrete in construction stages were proposed.

An Experimental Study on the Quality Control of Fresh Porous Concrete (굳지않은 포러스콘크리트의 품질관리를 위한 실험적 연구)

  • 이성일;장종호;김재환;강석표;백용관;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.705-710
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    • 2002
  • Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.

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A Study on the Application in Site of the Concrete Using Fly Ash Produced in Combined Heat Power Plant (열병합발전소 플라이애쉬를 사용한 콘크리트의 현장적용에 관한 연구)

  • 김무한;이상수
    • Journal of the Korea Concrete Institute
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    • v.11 no.5
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    • pp.41-49
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    • 1999
  • This study dealt with the applicability and quality control of the concrete using fly ash produced in combined heat power in a construction site. Firstly, chemical and physical characteristics of the fly ash produced in combined heat power plant re analysed. Also, after investigating the properties of flesh and hardened concrete through various experiments, the fly ash concrete was placed in depositing construction in Ulsan Petrochemical Service Co. This field application was focussed on the quality control system in the site as production, placing and curing of concrete. As the result of this study, the quantity of CaO in the fly ash is relatively high based on the chemical analysis. The fly ash concrete showed slumping maintenance and high viscosity properties in the optimal mixing conditions (W/B:44~45%, S/a:$45\pm$2%, W:185kg/m). And, quality control and assurance of the fly ash concrete in actual site were verified by various testing methods.

Properties of Recycled Concrete with High Quality Recycled Aggregate (고품질 재생 골재를 사용한 콘크리트의 특성)

  • Jong, Ji-Yong;Kawg, Eun-Gu;Kim, Jin-Man
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.384-387
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    • 2004
  • Though recycled aggregate is useful resources for concrete, its application to structural frame is not frequent, because of low quality of recycled aggregate. Owing to the development of manufacturing technology to recycled aggregate, it is possible to produce high quality recycled aggregate. The purpose of this study is to confirm the applicability of the high quality recycled aggregate, instead of the natural aggregate, to normal concrete. Main factors of this study are substitute proportion of recycled aggregate, types of recycled aggregate, targeting compressive strength of recycled concrete. From the results of the study, we concluded that it is possible to use high quality recycled aggregate, to get the same strength as concrete using normal aggregate.

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DESIGN MANAGEMENT FOR CONSTRUCTABILITY REVIEW OF HIGH QUALITY EXPOSED CONCRETE

  • Doo Won Hwang;Young woong Song;Yoon ki Choi;Dong Woo Shin;Jae Youl Chun
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1154-1157
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    • 2005
  • This report is to do design management for constructability review of high quality exposed concrete, which is used increasingly in recent. To secure systematic management at design phase, we reviewed each definition and work at each design phase, we define high quality exposed concrete, a part of architectural concrete, as "an exposed concrete which has well ordered joint & is in pursuit of smooth surface." We reviewed requirements and influential factor to obtain High quality finishing surface and compared construction process of high quality exposed concrete with that of other finishing method. Management method at each design phase for constructability review to meet additional works and requirements is presented.

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Efficient Unit-Water Management Method for Stabilizing the Quality of Ready-mixed Concrete (레미콘 품질 안정화를 위한 효율적인 단위수량 관리 방안)

  • Choi, Sung-Woo;Ryu, Deug-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.327-328
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    • 2021
  • In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

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