Recommendation of RILEM TC 260-RSC: testing sorption by superabsorbent polymers (SAP) prior to implementation in cement-based materials

The sorption of superabsorbent polymers (SAP) and kinetics of the process can differ significantly depending on SAP composition and grading as well as on properties of sorbed fluid. Several performance-oriented testing methods of SAP have been proposed in the literature to determine the individual sorption of polymers and to link them with their effects when embedded in cementitious materials as a multifunctional admixture. This recommendation focuses on the two main sorption capacity testing methods of free sorption assessment, the tea-bag and filtration methods. It includes experimental prescriptions to obtain consistent results and to draw conclusions as to whether or not a particular SAP is suitable for a cementitious material.