Temperature Modelling in Asphaltic Concrete Facings, the Reflective Surface Effect Simulation Case Study: Ghrib Dam (Ain Defla, Algeria)

Abstract

The asphaltic concrete facing is one of the most widely used components for waterproofing rockfill dams. It is, particularly in the case of hydroelectric pumped storage facilities, often highly exposed to significant temperature fluctuations, which are caused by solar radiation, variation in the water level in the reservoir, frost in the winter season, as well as wind speed and direction, and precipitation. To better explain the heat transfer phenomenon, it is necessary to know the temperature variations in the different layers of the asphaltic concrete facing. This study describes the measurement of the temperature in the asphaltic concrete facing (raw and protected) of the Ghrib dam (Ain Defla, Algeria) and its evaluation using a numerical model of the heat flow using the Fluent software. First, a validation of the model by comparison with experimental measurements, in the case of a daily variation in ambient temperature, the comparison of the results of the calculation of the numerical model with the real measurements shows an excellent similarity. Then we simulate the application of thermal protection by adding a reflective paint to the facing surface. The results of this simulation show that the reflection of solar radiation by the reflective surface has the potential to cool the asphaltic concrete facing and reduce the temperatures significantly, the temperature peak as well as reduce it to 11.47 °C, this happens at noon when the heat is very high, which is significant for our asphaltic concrete facing, where the temperatures reach their maximum values (49°C) in the raw case (without protection).