Thermal analysis of peak temperatures in massive wind turbine foundations

Wind turbine foundations are massive concrete structures in which controlling the temperature rise during the early-age curing process is of crucial importance for preventing cracking caused by thermal tensile stresses and for ensuring the durability of the concrete structure. This paper presents an example of a thermal analysis of three massive wind turbine foundations within a wind farm in the Republic of Serbia, based on the application of the finite element method. The thermal analysis included all relevant aspects of the thermal behavior of concrete-material parameters, boundary conditions, and construction dynamics. Variations in the initial temperature of the concrete mixture were considered in order to predict peak temperatures during the cement hydration process. The calculations were performed in accordance with relevant European and international standards and guidelines, including Eurocode and ACI. The results indicate exceedance of the peak temperatures prescribed by the regulations and the necessity of applying appropriate measures to reduce the temperature in the concrete. The obtained conclusions contribute to a better understanding of the presented thermal processes and emphasize the necessity of implementing measures to reduce peak temperatures in concrete. Exceeding peak temperatures, followed by long-term cooling and shrinkage of massive structures (toward the average ambient temperature), may cause the formation and development of cracks that negatively affect the quality and durability of massive concrete wind turbine foundations.