• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.305-308
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• 2003

Recently, a structure has been large and high under the improvement of construction technique. So, mass concrete constructions that a mat foundation thickness of structure is over 80cm have been many. Also, in the reason of high strength of concrete, a matter of thermal crack became an important task to be solved. In this study, we executed temperature and stress analysis of mat foundation. And we evaluated quantitatively about the possibility of thermal crack by using hydration heat analysis program. Because of this analysis technique, we could control skilfully the quality of mat foundation in a construction.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.1-4
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• 2003

Recently, a structure has been larger and higher under the improvement of construction technique. So, a mass concrete constructions that a mat foundation thickness of structure is over 80cm have been many. Also, because of the reason of high strength of concrete, the matter of thermal crack have become an important task to be solved absolutely. tn a cause of a thermal crack occurrence, there are material used, mixture of concrete, construction condition and so forth. In this study, we executed temperature and stress analysis of mat foundation to know the effect of the construction condition on a thermal crack of mat foundation. And we evaluated quantitatively about the occurrence possibility of thermal crack using the hydration heat analysis program. By using of this analysis technique, we will can control skilfully the quality of a mat foundation in advance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.385-390
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• 2001

The thermal crack in mass concrete is mainly due to the difference of concrete temperature, which is generated by hydration heat of cement. As the thickness of mat foundation increases, the difference of temperature becomes bigger. The purpose of this study is to estimate the optimum placing depth. The temperature of real mat foundation was observed and the thermal analysis by Finite Element Method was executed. Finally, the crack index according to the placing depth was estimated.

• 한국건축시공학회지
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• 제9권3호
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• pp.95-101
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• 2009

Constructing large-scale mat foundation mass concrete is increasing for the stability of building structure, because a lot of high rise building are being built in order to make full use of limited space. However, It is of increasing concerns that because limited placing equipments, available job-site and systems for mass concete placement in construction field do not allow to place great quantity of concrete at the same time in large scale mat foundation, consistency between placement lift can not be secured. And also, it is likely to crack due to stress caused by the difference of hydration heat generation time. To find out the solution against above problems, this study is to reconfirm the performance of normal concrete designed by mix proportion and super retarding concrete. The Fundamental test shows what happens if low heat proportioning and control method of setting time are applied at the job-site of newly constructed high rise building. The test result show that slump flow of concrete has been somewhat increased as the target retarding time gets longer, while the air content has been slightly decreased but this is no great difference from normal concrete. The setting time shows to be retarded as target retarding time gets longer, the range of retarding time increases. It is necessary to increase the amount of mix of super retarding agent in the proportion ration by setting curing temperature high since outdoor curing is about 6 hours faster than standard curing, which means the temperature of the concrete will be higher than the temperature of the surrounding environment, due to its high hydration heat when applying in a construction site. The compressive strength of super retarding concrete appears to be lower than normal concrete due to the retarding action in the early stage. However, as the time goes by, the compressive strength gets higher, and by the 28th day the strength becomes the same or higher than normal concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.979-984
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• 2002

The mat foundation of Tower Palace III is designed as a massive structure which has a 3.5m depth. The purpose of this study is to determine the optimum mix design having good workability and to control the actual concrete quality in site. For this purpose, we select the Self Compacting Concrete. Recently, the Self Compacting Concrete has been applied to achieve workability improvement. As the result of actual application, we have finished placing the mass concrete of 8, 000m$^3$ during 14hours with good success and obtain the good quality concrete. All test results are satisfied with our specifications for mat foundation and cut cost as the reduction of placing hours.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1169-1174
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• 2000

Since the cement-water reaction in exothermic by nature, the temperature rise within a large concrete mass. Significant tensile stresses may develop from the volume change associated with the increase and decrease of the temperature with the mass concrete. There thermal stresses will cause temperature-related cracking in mass concrete structure. These typical type of mass concrete include mat foundation, bridge piers, thick wall, box type walls, tunnel linings, etc. Crack control methods can be considered at such stages as designing, selecting the materials, and detailing the construction method. Temperature and analysis was performed by taking into consideration of the cement type and content, boundary and environment conditions including the variations of atmospheric temperature and wind velocity. This is paper, the effect of separate placement of thermal crack control footing was analysed by a three dimensional finite element method. As a result, using this method, thermal crack control can be easily performed for structures such as mat structures.

• 콘크리트학회지
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• 제13권1호
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• pp.31-36
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• 2001

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.29-30
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• 2020

In this study, as part of the foundation for advancing the material compounding aspect to reduce hydration heat cracks in the mat foundation on which the mass concrete is constructed, the degree of concrete varieties of cement is used. The setting time was measured and comparative analysis was performed. Results It was confirmed that the concrete using LHC was more effective than the concrete using OPC in reducing the use of SP, the calorific value of the concrete was low, and it was more effective in preventing cracks. It is also terminated after 10 hours and it is determined that the use of LHC can reduce the cracks caused by the heat of hydration of the mat foundation.

• 콘크리트학회지
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• 제7권6호
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• pp.167-175
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• 1995

본 연구에서는 매스콘크리트 양생시 수화열에 의한 온도 상승을 예측할 수 있는 온도해석 프로그램 $\boxDr$TAMCON$\boxUl$을 개발하였다. 수치해석 방법으로는 복잡한 형태를 지니고 다양한 경계조건을 만족시켜야 하는 구조물에 대한 온도해석을 용이하게 하기 위하여 유한요소법이 채택되었다. $\boxDr$TAMCON$\boxUl$의 타당성을 검증하기 위하여 벽상구조물과 기초매트에 대하여 이미 문헌에 보고된 수치해석 및 실험치를 본 연구의 해석 결과와 비교한 바 이들이 서로 잘 일치하고 있음을 확인하였다. $\boxDr$TAMCON$\boxUl$은 콘크리트 구조물의 온도균열 방지를 위한 온도제어 및 필요한 양생방법의 도입을 위한 시공관리에 효과적으로 활용될 수 있다.

• 콘크리트학회지
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• 제23권2호
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• pp.47-51
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• 2011