Improving Heat Exchange Performance of Massive Concrete Using Annular Finned Cooling Pipes

Cracks will be generated due to high internal temperature of the massive concrete. Postcooling method is widely employed as a standard cooling technique to decrease the temperature of the poured mass concrete. In this paper, an annular finned cooling pipe which can increase the heat transfer area between the flowing water and its surrounding concrete is proposed to enhance the cooling effect of the postcooling method. Analysis of the interior temperature variation and distribution of the concrete block cooled by the annular finned cooling pipe system and the traditional cooling pipe system was conducted through the finite element models. It is found that, for the concrete block using the proposed annular finned cooling pipe system, the peak value of the interior temperature can be further lowered. Compared with the traditional cooling pipe, the highest temperature of concrete with an annular finned cooling pipe appears earlier than that with the traditional cooling pipe.

Reduction of interior temperature of massive concrete using an enhanced heat transfer pipe array with spiral fins

The interior temperature of the massive concrete should be controlled to avoid cracks caused by the trapped hydration heat. In this paper, an enhanced heat transfer pipe array with spiral fins (PSF) is proposed to reduce the interior temperature of concrete blocks. Numerical simulations of massive concrete blocks embedded with traditional cooling water pipe (TCWP) and newly proposed PSF were conducted to investigate the interior temperature distribution of massive concrete. Meanwhile, validity of the finite element model was verified by both theoretical results and available experimental data. Based on the calculated temperature distribution of the points located in the interior area of the massive concrete, it is shown that when the TCWP was replaced by the PSF, the interior temperature can be significantly reduced. Therefore, compared to the TCWP, the proposed PSF has excellent heat transfer performance for cooling the interior temperature of massive concrete.

Building a nomogram to predict maximum temperature in mass concrete at an early age

During the construction of massive concrete structures, the main factor that affects the structure is temperature. The resulting temperature is the result of hydration of the cement and some other factors, which leads to the formation of thermal cracks at an early age. So, the prediction of temperature history in massive concrete structures has been a very important problem. In this study, with the help of numerical methods, a temperature nomogram was built to quickly determine the maximum temperature in concrete structures with different parameters such as size, cement content, and the initial temperature of the concrete mixture. The obtained temperature nomogram has been compared with the results of the finite element method and the model experiment gives reliable results. It can be used to predict maximum temperature in mass concrete structures to prevent the formation of thermal cracks.