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Experimental Study on Coefficient of Air Convection
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 Title & Authors
Experimental Study on Coefficient of Air Convection
Jeon, Sang-Eun; Kim, Jin-Keun;
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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 coefficient of air convection, which presents thermal transfer between surface of concrete and air, was experimentally investigated with variables such as velocity of wind and types of form. From experimental results, the coefficient of air convection was calculated using equations of thermal equilibrium. Finally, the prediction model for equivalent coefficient of air convection including effects of velocity of wind and types of form was theoretically proposed. The coefficient of air convection in the proposed model increases with velocity of wind, and its dependance on wind velocity is vaned with types of form. This tendency is due to a combined heat transfer system of conduction through form and convection to air. From comparison with experimental results, the coefficient of air convection by this model was well agreed with those by experimental results.
thermal property;coefficient of air convection;velocity of wind;type of form;
 Cited by
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