C-S-H sorption under temperature and relative humidity changes

Water vapor sorption measurements have positively contributed to the understanding of various phenomena affecting the durability and performance of cement-based materials. The temperature can have a great influence on these measurements. An in-depth research on the effect of temperature on sorption processes in cement-based materials informed by the molecular scale may offer new physical insights into understanding the phenomena. In this work, we aim to study water sorption in C-S-H. Specifically, we focus on the effect of temperature on water desorption in C-S-H at the molecular scale. Effective interactions and desorption isotherms are interpreted. Other features like water cavitation and stability under sorption are also analyzed. All these properties and features are investigated for temperatures between 27 and 150 °C through molecular simulation techniques. The influence of the pore size on the behavior of C-S-H under desorption is investigated. The effect of the temperature on the cohesion in C-S-H is also discussed. Cavitation shows a strong correlation with the temperature and the C-S-H pore size. The cohesion between the C-S-H layers increases with the temperature. These data can serve as valuable inputs for multi-scale models.