In-situ crosslinking of superabsorbent polymers as external curing layer compared to internal curing to mitigate plastic shrinkage

Abstract One way to externally cure a concrete surface is the use of a superabsorbent polymer layer, crosslinked in-situ. In this study, two biopolymers, being calcium alginate and gelatine, were studied as alternative compounds and compared to internal curing by means of superabsorbent polymers. Plastic shrinkage cracking tests were performed on fresh concrete, while monitoring the capillary pressure, the setting, the bleeding, the strength development and the microstructure. The external layer is effectively reducing while the internal curing method only partially mitigates the plastic shrinkage cracking potential. The best result is obtained when using calcium alginate as external layer.