Measurement and modeling concrete creep considering relative humidity effect

Relative humidity plays a critical role in concrete creep. To accurately measure and model creep behavior of concrete considering the relative humidity effect is difficult despite more than 100 years of research of concrete creep. In this study, a test set-up was designed to measure the creep-induced deflection of concrete beams exposed to different drying conditions (sealed and symmetric drying). A numerical method is proposed to quantify the creep parameters of concrete considering the relative humidity effect. The sequential coupled hydromechanical finite element analysis was conducted to back-calculate the creep parameters in the microprestress solidification theory-based creep model from the measured creep-induced deflection. It was found that the obtained parameters are independent of the loading and drying conditions. One set of parameters can predict the creep-induced deflection of concrete beams exposed to different drying conditions. The findings in this study provide a new methodology to obtain the creep parameters which can be implemented numerically for analyzing creep behavior of various concrete structures without considering the drying-related size effect.