• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.215-216
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• 2009

최근 품질관리, 소음저감 등의 이유로 자기충전 콘크리트의 적용사례가 증가하고 있어 이에 대처하기 위하여 저열 포틀랜드 시멘트를 활용하여 지하박스구조물에 일반강도에서의 저발열 자기충전 콘크리트를 개발하여 타설하였으며 이에 대한 배합설계 방법과 현장 적용방법 등을 제시하고자 한다.

• Advances in concrete construction
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• 제10권1호
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• pp.21-34
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• 2020

Precast deck joints have larger crack width than cast-in-place concrete decks. The initial crack typically occurs at the maximum moment but cracks on precast joints are significant and lead to failure of the deck. The present crack equation is applied to cast-in-place decks, and requires correction to calculate the crack width of precast deck joints. This research aims to study the crack width correction equation of precast decks by performing static tests using high strength and normal strength concrete. Based on experimental results, the bending strength of the structural connections of the current precast deck is satisfied. However it is not suitable to calculate and control the crack width of precast loop connections using the current design equation. A crack width calculation equation is proposed for crack control of precast deck loop joints. Also included in this paper are recommendations to improve the crack control of loop connections.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.367-370
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• 2003

This study was carried out to suggest the effective reinforcing method which can evaluate the tensile capacity of cast-in-place anchor with cracks. Currently, cast-in-place anchor is used widely for the fastening of equipment in Korean NPPs. 26 test specimens with a single anchor under 4 cracked conditions are prepared using plain concrete. The distance between crack and anchor and reinforcing materials were selected as the main test variable. The tensile force was applied using a actuator with a capacity of 100 tonf using a displacement control method of 0.5 mm/min velocity. Test results from this result show the combination of carbon plate and epoxy will be more available for repair and reinforcement of equipment foundation system in NPPs. Further experimental work is indeed involving the epoxy injection effect and adjustment of reinforcing location of carbon sheet.

• 한국항만학회지
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• 제10권2호
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• pp.69-90
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• 1996

This study is related to save the bearing capacity from using Meyerhof formula namely, static mechanics formula with the S.P.T(N value) of the soft ground and is to choose the soft ground improvement method by the using of total load for the proper method of the pile foundation and then to design the most suitable pile foundation to fit the actual circumstance. The purpose of this study is calculating the diameter of the pile foundation by static mechanics formula and introducing the optimum design condition from the result of the bearing capacity for using N value of the S.P.T obtained from the deep soft ground about the piles such as P.H.C pile, pipe and cast-in-place pile of big diameter, etc. As above-mentioned, it is considered that the use of P.H.C pile or pipe pile is advisable on the synthetical investigation and that the selection of cast-in-place pile method is desirable in terms of the constructive safety and durability.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.455-456
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• 2010

본 연구는 5000세대 이상 대규모 아파트 현장에서 사용되는 현장 타설 콘크리트의 효율적인 품질관리를 위해 동일 배합규격에 대하여 35개 레미콘 공장별 B/P TEST를 실시하여 굳지않은 특성 및 경화 특성을 검토한 것이다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.491-496
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• 2000

This paper presents the evaluation of behavior and the prediction of tensile capacity of anchors that fail concrete, as the design basis for anchorage. Tests of cast-in-place headed anchors, domestically manufactured and installed in uncracked, unreinforced concrete are performed to investigate the behavior of single anchors and multiple anchors with the consideration of various embedment lengths and edge distances. The failure mode and the load-deformation response of these anchors are discussed and the concrete failure dta are then compared with capacity predictions by the two existing methods : the 45 degree cone method of ACI 349, 318 and the concrete capacity design (CCD) method. Discrepancies between the test results and these two prediction methods, FEM analysis are assessed.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.672-680
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• 2005

There are a lot of reasons to use In-place tests. Construction schedules often require that operations such as form removal, post-tensioning, termination of curing, and removal of reshores be carried out as early as possible. To enable these operations to proceed safely as soon as possible requires the use of reliable in-place tests to estimate the in-place strength. In-place test results are not reliable for engineering judgment. These results should be interpreted and correlated to standard compressive strength, based on the test method. In this paper some of these test procedures and their limitations are discussed. In this study we will go on for Rebound number, Pullout, Ultrasonic pulse velocity, and Cast-in-place cylinder methods which are most useful methods in the Asia.

• 토지주택연구
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• 제3권2호
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• pp.169-175
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• 2012

최근, 지열 냉난방 시스템의 초기 공사비를 절감하기 위해 연구되고 있는 에너지 파일의 열교환량을 산정하기 위해 2종류(부속연결형, 슬링키형)의 현장타설말뚝형(PRD, 시공심도 4.5m, 직경 1,200mm) 에너지 파일을 시험시공하고 수치 시뮬레이션에 의해 효율을 상호 비교하였다. 상호 비교결과에 의하면 지중 교환량은 운전시작과 함께 채열에 의한 지중온도의 저하에 의해 점점 감소하였고 부속연결형의 평균 열원수의 온도차는 난방운전에서 $0.37^{\circ}C$, 냉방운전에서 $0.34^{\circ}C$로 나타났다. 또, 부속연결형의 난방운전시 열교환량 231.4W/m보다 냉방운전의 방열량은 252.2W/m로서 9% 높았고 슬링키형은 난방 기간 평균 열교환량이 168.0W/m로 부속연결형에 비해 약 27% 낮은 열교환량을 얻었다.

• 콘크리트학회지
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• 제16권2호
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• pp.57-61
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• 2004

• 한국강구조학회 논문집
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• 제27권1호
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• pp.87-97
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• 2015

본 연구에서는 균열콘크리트에 매입된 선설치앵커의 정적 전단하중에 대한 콘크리트 파열파괴강도 평가 실험을 수행하였다. 이를 위해 앵커 직경 30mm, 연단거리 150mm, 매입깊이 240mm인 비균열 시험체 2개와 전단하중에 수직한 방향과 평행한 방향의 균열을 모사한 시험체 각각 3개씩에 대해 실험을 수행하였다. 실험으로부터 하중 직각방향 균열 시험체는 비균열 시험체에 비해 강도의 저하가 없었으며 하중 평행 방향 균열 시험체는 91%의 강도를 보였는데, 이는 ACI 318-11의 비균열콘크리트의 저항강도의 84%에 해당하였다. 따라서 현재 ACI 318 기준에서 균열콘크리트의 저항강도를 비균열콘크리트 강도의 71%로 고려하는 것에 비해 작은 감소율을 보였다.