Nanoindentation creep of synthesized calcium-(alumino)-silicate-hydrate

The long term dimensional stability of concrete is crucial to long-lasting infrastructure and the primary binding phase (calcium-silicate-hydrate) is thought to be the primary phase responsible for viscoelastic behavior. Previous research indicates that the molecular structure of calcium-silicate-hydrate plays a role in viscoelastic behavior and is modified by changing the chemical composition, including the addition of aluminum into the structure. In this study, calcium-(alumino)-silicate-hydrate is synthesized with different molecular structure and tested for viscoelastic behavior using creep nanoindentation methods.

The data presented here are used to support the conclusion that micro-sliding of calcium-(alumino)-silicate-hydrate sheets relative to each other at interlayer sites is a source of viscoelastic behavior and that increased bonding and ionic correlation forces across the interlayer reduce the amount of time-dependent deformation. Supporting data include creep nanoindentation (load, displacement, and time), thermogravimetric analysis (temperature and weight loss), x-ray diffraction (diffraction angle and intensity), and solid-state nuclear magnetic resonance spectroscopy (chemical shift and intensity) for four different specimens with different molecular structures/chemical compositions.