A review and statistical study of existing hysteresis models for cementitious materials

• Hysteresis models developed for soils can be used for cementitious materials.
• For fitting of main curves, three-parameter models are more applicable.
• There are no good models to predict one main curve from the other one.
• Empirical hysteresis models yield better results, but pumping errors are problematic.
• Conceptual models show no pumping errors and can be used for further modeling.

Hysteretic behavior of water vapor sorption isotherms (WVSIs) has been widely recognized as one of the main factors which can significantly affect moisture transport within building materials exposed to natural weather conditions. Due to the lack of experimental data for validation, there are few studies about hysteresis models in the field of cementitious materials. In this paper, a detailed review of hysteresis models has been presented. Models which have been initially developed for water transport in soils and sands have been selected, including the conceptual and empirical models. The comprehensive comparisons with experimental data have been performed for cement pastes and concretes. It enables to conclude a set of best models for prediction of WVSIs and their hysteresis. Comparison results show that for the prediction of the first scanning curves, available hysteresis models (either conceptual or empirical) perform similarly. However, studied empirical models yield pumping errors for the secondary or higher order scanning loops. A multi-level hysteresis modeling has been proposed as well. Evaluations and recommendations for use of this multi-level modeling method have been provided for an application purpose of compared models.