Loading history dependence of retardation time of calcium-silicate-hydrate

Calcium-silicate-hydrate (C-S-H) exhibits a viscous effect, which significantly affects long-term deformation of concrete. In this study, treated cement pastes are examined to investigate the viscous effect of C-S-H. Creep experiments are performed by the nanoindentation technique, and the results indicate that creep deformation in the dwelling period is dependent on loading history. This phenomenon can be explained by the motion activation of different kinematic elements of C-S-H as well as micro-damage evolution. Further analysis indicates that the effect of loading rate and magnitude of creep load on retardation time approximately follows a power-law.