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

• Published in: Construction & building materials 2020-11, Vol.262, p.120819, Article 120819
• Main Authors: Snoeck, D., Moerkerke, B., Mignon, A., De Belie, N.
• Format: Article
• Language: English
• Subjects: Curing; Hydrogel; Plastic shrinkage; Synthesis
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2020.120819

[Display omitted] •An external curing layer prevents evaporation from the concrete substrate.•The use of biopolymers as an external curing layer is practically feasible.•An external calcium alginate layer mitigates plastic shrinkage and reduces cracking.•Gelatine is less effective as a curing layer compared to calcium alginate.•Internal curing by superabsorbent polymers partially mitigates plastic shrinkage. 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.