Time-dependent shrinkage and creep-induced prestress loss of vari-size PC beams considering the typical climate in China

Accurately predicting the time-dependent prestress loss in prestressed concrete (PC) structures is essential for ensuring their long-term service life and structural safety. However, long-term prestress loss varies significantly across different climatic conditions, highlighting the urgent need for a simplified yet effective method to predict prestress loss under representative environmental scenarios. Using a multi-physics and multi-scale computational approach, this study predicted the long-term prestress variation under various representative environmental conditions, characterized by monthly average temperature and humidity spectra of typical cities. Accordingly, applying multiple levels of temporal averaging temperature and humidity records for Hangzhou to quantify the discrepancies among monthly, seasonal, and annual average environmental spectrum. Results show that monthly average environmental spectrum can serve as a surrogate for numerical analysis to a reasonable extent. Based on the comparison with the calculated values from the European codes CEB-FIP 1990 and fib 2010, as well as the Chinese code GB 50010-2010, coefficient of correction for GB 50010-2010 model code ( μ GB ) are proposed. The results indicate that the most of μ GB ranges from 1.0 to 1.6 and it is recommended that the Chinese code be revised to incorporate appropriate coefficient of correction calculated by proposed calculating model to ensure the structural safety of PC structures designs.