Superabsorbent polymers (SAPs) have already found their way in many applications. Interestingly so-called 'smart' polymers undergo major characteristic changes by small environmental variations. Characterization of these 'smart' SAPs is of the utmost importance. In the present work, copolymers consisting of among other acrylic acid and acrylamide have been synthesized, followed by the characterization of their moisture uptake capacity and their swelling capacity in aqueous solutions. Subsequently, these SAPs have been introduced in mortar samples and the resulting strength and water permeabili!ty has been monitored. Two commercially available SAPs and a cross-linked Pluronic-based SAP have also been evaluated. The results indicate that the moisture uptake capacity at high relative humidities increased 90 % of the original polymer weight with almost no hysterisis occurring. In addition, these low-cross linked SAPs show their highest swelling degree (i.e. up to 450 times their original weight) at pH 12. Additional results indicated that one of the commercially available SAPs (i.e. SAP B) results in the smallest drop in strength and the lowest water permeability factor k. The results also demonstrated that the Pluronic-type SAPs were not useful for the application considered. The developed SAPs can still be improved, but already show a reasonable self-sealing effeciency.