Kinetics of Water Migration in Cement-Based Systems Containing Superabsobent Polymers

Superabsorbent polymers (SAP) absorb pore solution during mixing of concrete and release it when cement paste self-desiccates or is exposed to drying. Knowledge of the kinetics of water migration in and out of the SAP is essential for understanding and optimizing internal curing of concrete. This chapter discusses absorption of pore solutions in SAP and desorption of the SAP, both in model systems and in cement paste or concrete. When experimental results about SAP are missing in the literature, results obtained with other internal curing agents are presented and the applicability to SAP is discussed. A final section is dedicated to modeling of internal curing of concrete by SAP and especially to modeling of water migration to and from the SAP.