DURABILITY ANALYSIS OF CONCRETE FOR UNDERGROUND THERMAL ENERGY STORAGE

Underground thermal energy storage (UTES) is a promising approach for large-scale and long-term energy storage and has attracted significant interest in recent years worldwide. Ensuring the stability and durability of UTES structures is crucial for long-term functionality and serviceability. However, the UTES facilities may experience concrete degradation over time, compromising the efficacy of thermal energy storage. Comprehensive research on the endurance of concrete materials for thermal energy storage is still lacking. This study proposes an experimental strategy by designing a bespoke multiphysics experimental system to replicate the in-situ conditions (e.g. temperature fluctuation, pore pressure change and chemical corrosion) during thermal energy storage. By analysing the concrete mechanical degradation and microstructure evolution, the failure mechanisms of concrete materials under multi-physical environments could be clarified and the UTES service life could be predicted.