A Material Bending Tensile Stress–Strain–Time–Temperature Creep Model for Analyzing Asphalt Reservoir Facings of Daily Pumped Storage Projects

Pumped storage projects are effective engineering measures for transforming unstable solar energy and wind energy into stable hydro energy. The geological and topographical conditions in the top areas of mountains are complex for most upper reservoirs of pumped storage projects. Flexible asphalt concrete is usually used as the impervious reservoir facing to suit the complex geological and topographical conditions. The asphalt facing is subject to daily loading and unloading in the temperature range −10 °C to 20 °C, as the temperature of water in the reservoir is in the range 0 °C to 20 °C. Asphalt concrete beam bending creep tests were carried out in the temperature range −10 °C to 20 °C to determine the overall performance of asphalt facing. Based on the Burgers model in viscoelastic theory, a material bending tensile stress–strain–time–temperature creep (TSSTTC) model is proposed for analyzing asphalt concrete reservoir facings of daily pumped storage projects. Tensile and compressive behaviors for asphalt bending are analyzed. Tests were conducted to simulate the asphalt facing subjected to loading–unloading cycles due to the filling and discharging of the reservoir. Test results under different loading conditions are compared and analyzed. The performance of asphalt reservoir facings of daily pumped storage projects is discussed.