Experimental study on heat transfer coefficient in convection flow of young concrete at pipe cooling

Pipe cooling is widely used for reducing hydration heat and controlling cracking in mass concrete structures. However, in order to effectively apply pipe cooling systems to concrete structures, the coefficient of convection flow representing the thermal transfer between inner stream of pipe and concrete must be accurately estimated. In this study, a device measuring the coefficient of convection flow is developed. The main influencing factors in the coefficient of convection flow are stream flow velocity and pipe diameter, thickness, and material. Also, a prediction model of the coefficient of convection flow is proposed using experimental results from the developed device. The analytical results using the proposed prediction model show that the coefficient of convection flow increases with the increase in flow velocity, and decreases with the increase in pipe diameter and thickness. Also, the coefficient of convection flow is strongly affected by pipe materials.