• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.81-84
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• 2002

Activation energy value is different according to cement, admixture and water-cement ratio also the relation of age-temperature is as non-linear as activation energy value is large. So to make accurate explanation for the effect of temperature on concrete strength development property, it is necessary to investigation for activation energy value. This study compares activation energy value recommended by Freiesleben and ASTM with activation energy value obtained by consequence of mortar examination according to ASTM C 1074-93. As the result of this study, activation energy value obtained by the study is 37.19KJ/mol, and in case of activation energy value obtained by the study explain temperature's influence about concrete strength development more accurate than activation energy value recommend by Freiesleben and ASTM.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.947-952
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water/cement ratio. Based on the regression results, the influence of fly ash replacement content and water/cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water/cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water/cement ratio. But, the concrete with water/cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water/cement ratio.

• 콘크리트학회논문집
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• 제12권2호
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• pp.31-42
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• 2000

This paper discusses the validity of models predicting the compressive strength of concrete subjected to various temperature histories and the shortcomings of existing rate constant model and apparent activation energy concept. Based on the discussion, a modified rate constant model is proposed. The modified rate constant model, in which apparent activation energy is a nonlinear function of curing temperature and age, accurately estimates the development of the experimental compressive strengths by a few researchers. Also, the apparent activation energy of concrete cured with high temperature decreases rapidly with age, but that of concrete cured with low temperature decreases gradually with age. Finally generalized models to predict apparent activation energy and compressive strength are proposed, which are based on the regression results.

• 한국방사선학회논문지
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• 제13권1호
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• pp.45-53
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• 2019

본 연구는 의료용 선형가속기 시설을 차폐하는 콘크리트에 대한 중성자 방사화 연구로써, 일반 콘크리트와 저 방사화 콘크리트를 비교 분석하였다. 실험 방법은 MCNPX (Ver. 2.5.0)와 FISPACT-2010를 사용하여 모의실험을 진행하여, 광자선과 중성자선에 대한 차폐능을 산정하고 중성자 방사화 평가를 진행하였다. 그 결과 차폐능은 일반 콘크리트에서 20~50 cm 효율적이였으며, 방사화 평가의 경우 저 방사화 콘크리트에서 방사능이 낮게 계산되었으나, 모두 자체처분허용 농도를 초과하지 않는 수준으로 산정되었다. 이를 종합적으로 분석한 결과 일반 콘크리트를 사용하는 것이 효율적인 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문 발표회
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• pp.13-16
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• 2003

There is no study that application of the maturity using H.B.C and H.S.C. Also activation energy has different values according to the cement, admixture and water-cement ratio. Therefore to make accurate explanation for the effect of temperature on concrete strength development properties, it is necessary that activation energy value according to the kind of cement is reviewed. This study compares and estimates equivalent age using activation energy value obtained by this experiment and Freiesleben activation energy value with compressive strength of concrete. As the result of this study, activation energy value obtained by this study has more accurate explanation of temperature's influence on concrete strength development than Freiesleben activation energy value.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.13.1-16
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• 2003

There is no study that application of the maturity using H.S.C and H.S.C. Also activation energy has different values according to the cement, admixture and water-cement ratio. Therefore to make accurate explanation for the effect of temperature on concrete strength development properties, it is necessary that activation energy value according to the kind of cement is reviewed. This study compares and estimates equivalent age using activation energy value obtained by this experiment and Freiesleben activation energy value with compressive strength of concrete. As the result of this study, activation energy value obtained by this study has more accurate explanation of temperature's influence on concrete strength development than Freiesleben activation energy value.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.155-158
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• 1999

This paper discusses the validity of models to predict the compressive strength of concrete subjected to various temperature histories and the shortcomings of existing rate constant model and apparent activation energy concept. Based on the discussion, a modified rate constant model is proposed. The modified rate constant model, in which apparent activation energy is a nonlinear function of curing temperature and age, accurately estimates the development of the experimental compressive strengths by a few researches. Also, the apparent activation energy of concrete cured with high temperature decreases rapidly with age, but that cured with low temperature decreases gradually with age. Finally a generalized model to predict apparent activation energy and compressive strength is proposed, which is based on the regression results.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.60-61
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• 2019

Concrete carbonation is one of the factors that reduce the durability of concrete. In modern times, due to industrialization, the carbon dioxide concentration in the atmosphere is increasing, and the impact of carbonation is increasing. So, it is important to understand the carbonation resistance according to the concrete compounding to secure the concrete durability life. In this study, we want to predict the concrete carbonation velocity coefficient, which is an indicator of the carbonation resistance of concrete, through the deep learning algorithm, and to find the activation function suitable for the prediction of carbonation rate coefficient as a process to determine the learning accuracy through the deep learning algorithm. In the scope of this study, using the ReLU function showed better accuracy than using other activation functions.

• 콘크리트학회논문집
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• 제13권3호
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• pp.237-243
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• 2001

본 논문에서는 플라이애시 콘크리트의 재령에 따른 변화를 예측하기 위한 모델식을 제시하고 그 모델식의 유효성을 검토하였다. 기존에 행해졌던 실험결과를 모델식을 이용하여 회귀분석한 후에 그 결과를 플라이애시 대체량과 물-시멘트비에 따라 분석하였다. 해석결과에 의하면 예측 모델식은 실험결과를 일정오차내에서 잘 모델링하였다. 그러나 물-시멘트비가 매우 작은 경우에는 플라이애시 대체량이 증가하면 실험값과 예측값의 오차가 조금 증가하는 경향을 나타내었다. 플라이애시 대체량이 증가할수록 한계상대압축강도의 크기가 증가하였고 초기 겉보기 활성에너지도 한계상대압축강도와 같이 플라이애시 대체량이 증가할수록 증가하였다. 0.40이하의 물-시멘트비에서는 한계상대압축강도와 겉보기 활성에너지의 크기가 일정하고 물-시멘트비가 0.40을 초과하면 물-시멘트비의 증가에 따라 한계상대압축강도와 겉보기 활성에너지가 조금씩 증가하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.101-102
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• 2021

The compressive strength of concrete is greatly affected by the temperature inside the concrete at the initial age immediately after pouring. The apparent activation energy of cement and the setting time of concrete are major factors influencing the development of compressive strength of concrete. This study measured the apparent activation energy and setting time according to the change in W/B for each mixing rate of Ground Granulated Blast-Furnace Slag (GGBFS). And after calculating the compressive strength prediction model, the accuracy of the prediction model was evaluated by comparing the predicted compressive strength and the compressive strength.