Accelerated and long-time creep testing of extruded polystyrene using isothermal and stepped isothermal method

Seasonal Sensible Thermal Energy Storages based on existing inside structures are cost effective and require insulation materials with high performance. The must endure temperatures pressure for a long period. In this study, the creep effects of material XPS (extruded polystyrene foam) at investigated to determine whether is suitable be applied STES. Two studies were conducted: an isothermal long-term experiment SIM (Stepped Isothermal Method) experiment. results first study fitted using Findley approach extrapolated 50 years. method accelerate thermal Boltzmann superposition principle. Creep strain after years directly calculated by extrapolation. Both indicate that in remains well below 6% load 61.1 kPa 60 °C Additionally, model predicts different or varying stress was developed data.