[논문]혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리

이동율; 함수윤; 오태근

doi:10.14346/jkosos.2015.30.3.59

혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리
The Effective Control of Hot Weather Concreting by Optimum Mineral and Chemical Admixtures 원문보기

한국안전학회지 = Journal of the Korean Society of Safety, v.30 no.3, 2015년, pp.59 - 66

이동율 (인천대학교 안전공학과) , 함수윤 (일리노이주립대학교 토목공학과) , 오태근 (인천대학교 안전공학과)

초록
AI-Helper

본 연구는 슬럼프 감소, 연행 공기 부족, 건조수축 균열, 강도감소 등 굳지 않은 콘크리트와 굳은 콘크리트의 성질에 대한 타설시 고온의 악영향에 대한 원인분석을 실시하고 이를 경감시키기 위한 감수제, 공기연행제, 지연제 등의 화학적 혼화제와 플라이 애쉬, 고로 슬래그 등의 무기질 혼화재의 다양한 적용이 검토되었다. 즉, 서중 콘크리트의 품질향상을 위한 다양한 콘크리트 배합이 설계되고 각 배합에서의 굳지 않은 콘크리트 및 굳은 콘크리트 에 대한 영향이 분석되고 몇 가지의 최적 배합이 도출되었다.

Abstract ▼ AI-Helper

The undesirable effects of elevated external temperatures at placement on the properties of the fresh and hardened concrete are discussed briefly, and the possible use of the mineral admixtures to mitigate them and the association with water-reducing and retarding admixtures in terms of the mix design which are critical for minimizing slump loss and entrained air loss are examined in this study. To investigate the effects of such the mineral and chemical admixtures on the fresh and hardened properties of concrete exposed to high temperature, a series of concrete mixtures subjected to the high temperature were carried out and then fresh and hardened properties of the mixtures were analyzed and evaluated. Based on the results, new guide lines concerning the appropriate admixtures for hot weather are suggested.

주제어

AI 본문요약
AI-Helper

* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.

문제 정의

The objective of this study is to design and evaluate proper mixtures to maintain to suitable characteristics under a high temperature mixing and placement environment. A range of concrete mixtures were subjected to an extended high temperature mixing procedure.
The effects of these factors on the strength of hardened concrete are also investigated. Thus, the objective of this study is to develop a better understating of the effects of higher temperatures on the properties of concrete with new finding.

가설 설정

A number of measures have been used to mitigate undesirable effects under the high temperature^1,2); the mix design with good performance in hot weather; cooling materials by chilled water and ice, or liquid nitrogen; concrete consistency that allows rapid placement and consolidation; and limiting the maximum in-place temperature. However, there have been many debates about the treatments; the temperature limit applied to concrete in hot weather is effective? ; the production cost of concrete is reasonable when ice or refrigeration is used?

제안 방법

This process demonstrated that concrete mixtures that are not altered during high temperature application will certainly lead to potential problems with placement, compaction, and finishing, and in all likelihood, future durability issues also. For this study, the FDOT procedure identified the combination of material constituents that were able to achieve workable, compactable, and finishable concrete that meets IDOT specifications. It also was able to indicate potential interactions that could result in problems in the initial construction or long-term durability.
In this study, to investigate the effects of mineral and chemical admixtures on the performance of fresh concrete at higher temperatures, a series of concrete mixtures subjected to the high temperature mixing procedure were carried out. Based on the results, new guide lines concerning the appropriate admixtures for hot weather are suggested.
The high temperature extended mixing procedure developed by FDOT was successfully applied to several different concrete mixtures with varying mineral and chemical admixture content. Slump and air content were measured before and after the extended procedure for each mixture, and strengths of companion samples were measured at 3, 7, and 14 days. According to IDOT specifications for “PV” (pavement) concrete, slump should be between 2 to 4 inches (50.
The mixtures contained different amounts and types of mineral and chemical admixtures. The performance of the fresh mixtures was evaluated by slump and air content tests. The compressive and split tensile strength of samples cast from the mixtures was also measured.
Air content and slump were measured before and after the 90-minute mixing procedure as well as compressive and splitting tensile strengths at various ages. The principal goals of the tests were to determine the effects of mineral and chemical admixtures on the performance of fresh concrete at high temperatures and to meet the minimum strength at 14 days. Tests to measure early-age cracking tendency and long-term material durability performance of the material were not carried out here, but still need to be conducted.
Tests to measure early-age cracking tendency such as the restrained ring shrinkage test and long-term material durability performance such as freezing and thawing resistance and scaling of the material were not carried out here. These issues should be studied to complete a comprehensive evaluation of the behavior of concrete subjected to high temperatures later.
Based on the results, new guide lines concerning the appropriate admixtures for hot weather are suggested. This research focuses on the proper design of mixing and placing concrete in hot weather and various aspects are examined: mixing portions, delay time between mixing and placing and admixtures. The effects of these factors on the strength of hardened concrete are also investigated.

참고문헌 (10)

ACI Committee 305, Hot Weather Concreting, American Concreting Institute, Farmington Hills, Michigan, 2002.
P. K. Mehta and W. Langley, "Monolith Concrete Foundation: Built to Last a 1000 Years", Concrete International, Vol. 22, No. 7, pp. 27-32, 2000.
P. K. Mehta, "Performance of High Volume Fly Ash Concrete in Hot Weather", Innovations in Design with Emphasis on Seismic, Wind, and environmental Loading; Quality Control and Innovations in Materials / Hot Weather Concreting, Proceedings, ACI Fifth International Conference, Cancun Mexico, December, 2002.
M. Samarai, S. Popovics and V. M. Malhotra, "Effect of High Temperatures on the Properties of Fresh Concrete", Transportation Research Record, Vol. 924, pp.42-50, 1983.
W. Ma, D. Sample R. Martin and P. W. Brown, "Calorimetric Study of Cements Blends Containing Fly Ash, Silica Fume and Slag at Elevated Temperatures", Cement Concrete and Aggregates, Vol. 16, No. 2, pp. 93-99, 1994.

상세보기
Illinois Department of Transportation, "Standard Specifications for Road and Bridge Construction", IDOT, 2007.
Florida Department of Transportation, "Standard Specifications for Road and Bridge Construction", FDOT, 2009.
A. R. Chini and L. Acquaye, "Effect of Elevated Curing Temperatures on the Strength and Durability of Concrete", Materials and Structure, Vol. 38, No. 8, 673-679, 2005.
A. Salas, J. Roesler and D. Lange, "Properties of Recycled Aggregate Concrete", Technical Note 43 for O'Hare Modernization Program, University of Illinois, 2009.
S. D. Kohn and S. Tayabji, "Best Practices for Airport Portland Cement Concrete Pavement Construction (Rigid Airport Pavement)", Report IPRF-01-G-002-1, An IPRF Research Report Innovative Pavement Research Foundation Airport Concrete Pavement Technology Program, 2003.

내보내기 구분	파일저장 인쇄 메일전송
구성항목	기본정보 상세정보 관리번호, 논문명, 저널/프로시딩명, 저자 , 발행년, 권, 호, 시작페이지, 끝페이지, 발행기관 관리번호, 논문명, 대등논문명, 저자 , 저널/프로시딩명, 발행기관, 발행년, 발행언어, 권, 호, 시작페이지, 끝페이지, ISBN, ISSN, 주제분야, 키워드, 초록(한글), 초록(영문), 저자(소속기관)
저장형식	Text(ASCII format) Excel format RefWorks Direct Export RIS format (for Reference Manager, ProCite, EndNote), Scholar's Aids, Mendeley
메일정보	받는사람 (필수) @ 보내는사람 (선택) @ 제목 내용 KISTI 검색결과 이메일 서비스
안내	총 건의 자료가 검색되었습니다. 다운받으실 자료의 인덱스를 입력하세요. (1-10,000) 검색결과의 순서대로 최대 10,000건 까지 다운로드가 가능합니다. 데이타가 많을 경우 속도가 느려질 수 있습니다.(최대 2~3분 소요) 다운로드 파일은 UTF-8 형태로 저장됩니다. 파일의 내용이 제대로 보이지 않을실 때는 웹브라우저 상단의 보기 -> 인코딩 -> 자동선택 여부를 확인하십시오. ~ Text(ASCII format) Excel format

연합인증

혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리
The Effective Control of Hot Weather Concreting by Optimum Mineral and Chemical Admixtures 원문보기

초록
AI-Helper

Abstract ▼ AI-Helper

주제어

AI 본문요약
AI-Helper

문제 정의

가설 설정

제안 방법

참고문헌 (10)

이 논문을 인용한 문헌

저자의 다른 논문 :

관련 콘텐츠

원문 보기

원문 URL 링크

오픈액세스(OA) 유형

이 논문과 함께 이용한 콘텐츠

AI-Helper ※ AI-Helper는 오픈소스 모델을 사용합니다.

선택된 텍스트

연합인증

혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리 The Effective Control of Hot Weather Concreting by Optimum Mineral and Chemical Admixtures 원문보기

초록 용어보기논문에서 용어와 풀이말을 자동 추출한 결과로, 시범 서비스 중입니다. AI-Helper

Abstract ▼ AI-Helper

주제어

AI 본문요약 엑셀 다운로드 AI-Helper

문제 정의

가설 설정

제안 방법

참고문헌 (10)

이 논문을 인용한 문헌

저자의 다른 논문 :

이동율 (4) 오태근 (75)

관련 콘텐츠

원문 보기

원문 URL 링크

오픈액세스(OA) 유형

이 논문과 함께 이용한 콘텐츠

AI-Helper ※ AI-Helper는 오픈소스 모델을 사용합니다.

선택된 텍스트

혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리
The Effective Control of Hot Weather Concreting by Optimum Mineral and Chemical Admixtures 원문보기

초록
AI-Helper

AI 본문요약
AI-Helper