Determination of Convection Heat Transfer Coefficient Considering Curing Condition, Ambient Temperature and Boiling Effect

- Journal title : Journal of the Korea Concrete Institute
- Volume 17, Issue 4, 2005, pp.551-558
- Publisher : Korea Concrete Institute
- DOI : 10.4334/JKCI.2005.17.4.551

Title & Authors

Determination of Convection Heat Transfer Coefficient Considering Curing Condition, Ambient Temperature and Boiling Effect

Choi Myoung-Sung; Kim Yun-Yong; Woo Sang-Kyun; Kim Jin-Keun;

Choi Myoung-Sung; Kim Yun-Yong; Woo Sang-Kyun; Kim Jin-Keun;

Abstract

The setting and hardening of concrete is accompanied with nonlinear temperature distribution caused by development of hydration heat of cement. Especially at early ages, this nonlinear distribution has a large influence on the crack evolution. As a result, in order to predict the exact temperature history in concrete structures it is required to examine thermal properties of concrete. In this study, the convection heat transfer coefficient which presents thermal transfer between surface of concrete and air, was experimentally investigated with variables such as velocity of wind, curing condition and ambient temperature. At initial stage, the convection heat transfer coefficient is overestimated by the evaporation quantity. So it is essential to modify the thermal equilibrium considered with the boiling effect. From experimental results, the convection heat transfer coefficient was calculated using equations of thermal equilibrium. Finally, the prediction model for equivalent convection heat transfer coefficient including effects of velocity of wind, curing condition, ambient temperature and boiling effects was theoretically proposed. The convection heat transfer coefficient in the proposed model increases with velocity of wind, and its dependance on wind velocity is varied with curing condition. This tendency is due to a combined heat transfer system of conduction through form and convection to air. From comparison with experimental results, the convection heat transfer coefficient by this model was well agreed with those by experimental results.

Keywords

thermal property;convection heat transfer coefficient;velocity of wind;ambient temperature;boiling effect;

Language

Korean

Cited by

1.

뿜칠피복재를 사용한 고강도 콘크리트 부재의 내화피복두께에 관한 실험적 연구,이태규;

한국화재소방학회논문지, 2010. vol.24. 4, pp.41-46

References

1.

Rastrup, E, 'Heat of Hydration in Concrete', Magazine of Concrete Research, Vol.6, No.17, 1954, pp.79-92

2.

Hsieh, C, Qin, C, and Ryder, E, Development of Computer Modelling for Prediction of Temperature Distribution Inside Concrete Pavements, Report FL/DOT/SO/90-374, Mechanical Engineering Dept, University of Florida, Gainesville, 1989, pp.32-59

3.

Chapman, Fundamental of Heat Transfer, Macmillian Inc., New York, 1982, pp.6-79

4.

Fermando, A B., Mendes, P. A, and Mrambell, E, 'Heat of Hydration Effects in Concrete Structures', ACI Materials Journal, Vol.89, No.3, 1992, pp.139-148

5.

Mendes, P. A, Temperature Gradients for Concrete Bridges, MSc thesis, Technical University of Lisbon, 1989, pp.78-114

6.

四國電力(株), マスコンクリ-トの初期ひび割れとその防止對策に關する硏究, 1964, pp.36-70

7.

山川, 笠原, 小林, 'マスコンクリ-トの熱傳導率試驗方法の檢討' 弟37回土木學會年次學術講演會槪要集, 弟5部, Vol.37, No.5, 1982, pp.27-64

8.

小澤章三, マスコンクリ-トの初期ひび割れとその防止對策に關する硏究(I), 發電水力, No.57, 1962, pp.254-261

9.

김국한, 전상은, 방기성, 김진근, '콘크리트의 열전도율에 관한 실험적 연구', 콘크리트학회논문집, Vol.13, No.4, 2001, pp.305-313

10.

이택식, 이재현, 이준식, 열전달, 희중당, 1992, pp.14-61

11.

Eckert. E R G., and R M. Drake, Analysis of Heat and Mass Transfer, Mcgraw-Hill, New York, 1972, pp.10-39

12.

Kang, Y. M. and Park, G. C., 'An experimental Study on Evaporative Heat Transfer Coefficient and Applications for Passive Cooling of AP600 Steel Containment', Nuclear Engineering and Design, 204, 2001, pp.347-359

13.

Billard, Y, Shekarchi, M, Debicki, G., Granger, L, and Chauvel, D., 'Heat and Mass Transfer in a Concrete Wall with Composite Linear under Accidental Conditions', Nuclear Engineering and Design, 228, 2004, pp.261-272

14.

Kapila, D., Falkowsky, J., and Plawsky, J., 'Theraml Effects During the Curing of Concrete Pavement', AG Material Journal, Vol.94, No.2, 1997, pp.119-128

15.

Hsieh, C. and Qin, C., 'Characterization of Thermal Properties of Concrete and Temperature Prediction Model', Journal of Korea Concrete Institute, Vol.9, No.2, 1997, pp.121-132

16.

Thomas, L. C., Heat Transfer, Prentice-Hall International, New Jersey, 1992, pp.463-502

17.

Kapila, D., Falkowsky, J., and Plawsky, J., 'Theraml Effects During the Curing of Concrete Pavement', ACI Material Journal, Vol.94, No.2, 1997, pp.119-128

18.

Machida, N. and Uehara, K, 'Nonlinear Thermal Stress Analysis of A Massive Concrete Structure', Computer & Structures, Vol.26, No.26, 1987, pp.287-296

19.

Kim, J. K. and Yang, E. I., 'Factors for Hydration Heat and Thermal Stress in Mass Concrete', Journal of Korea Concrete Institute, Vol.9, No.3, 1997, pp.15-23