Prediction and control of temperature rise of massive reinforced concrete transfer slab with embedded cooling pipe

Abstract

Reinforced concrete (RC) transfer slabs (or beams) are common support structures for high-rise or multi-use buildings. The structure serves as a new base for the upper zones and transfers considerable loads to the foundation; hence, the RC transfer slab necessitates a massive thickness design, as well as the use of high-strength material, and should be constructed without cracks. In this paper, the temperature rise of the massive RC transfer slab controlled by embedded cooling pipes was predicted by the Ansys program, and the numerical prediction was verified by recorded data of the temperature rise of the massive RC transfer slab. Regarding to the temperature rise, both prediction data and recorded data showed that, initially, the temperature at the bottom surface and the core of the RC transfer slab rose fast, resulting in a substantial temperature differential (20.4 °C) with the top surface, and, during the cooling stage, the top surface then retained heat and cooled more slowly than the bottom surface; moreover, the model fitted quite well with the measurement at the peak temperature. Regarding cooling pipe operation, within the first four days, it was recommended that the flow rate of 30 °C cooling water was set as high as 26.5 L/m (liters/minute), and this number was subsequently increased to 30 L/m when the temperature differential within the concrete peaked at 20 h.

Keywords

• Artificial cooling system
• Field assessment
• Mass concrete
• Numerical simulation
• RC transfer slab
• Thermal control plan