Recent progress in superabsorbent polymers for concrete

Scientific interest on superabsorbent polymers (SAPs) in conjunction with cement-based building materials has widened from mostly engineering aspects towards polymer physico-chemical topics over the past years. Here, we focus on the relationships between absorptivity in terms of absorption/desorption kinetics and retention of the absorbed liquid and the polymer physico-chemical principles. Based on such understanding, use and effects of SAPs in concrete are outlined and explained mechanistically. They comprise modifying rheology, internal curing to mitigate plastic and autogenous shrinkage, self-sealing and self-healing of cracks, and improvement of freezing-and-thawing durability. Recent topics such as reduction of fire spalling and enhanced growth of plant species on green wall facades are also explored for advancing the applications of SAPs in cement-based materials.