Evaluation of Agar-Based Seaweed and Kelp Coatings as Sustainable Protective Materials for Cement Surfaces
Seojun Lee
Korea International School, Pangyo, South Korea
Publication date: July 20, 2026
Korea International School, Pangyo, South Korea
Publication date: July 20, 2026
DOI: http://doi.org/10.34614/JIYRC2026I02
ABSTRACT
This study evaluated agar-based coatings incorporating seaweed and kelp biomass as sustainable protective materials for cement surfaces. Agar, seaweed, kelp, and gelatin were initially assessed individually for gelation and film-forming behavior, followed by testing of combined formulations for structural integrity, surface cracking, UV resistance, and water absorption. Agar was the only individual material that formed a stable hydrogel, and agar-based mixtures with seaweed or kelp successfully formed solid coating films, whereas gelatin-based mixtures remained liquid. Among the tested formulations, the 1.5 g agar–seaweed and 1.5 g agar–kelp coatings showed the best performance, forming more uniform films with fewer cracks, reduced water absorption, and reduced microcrack formation after UV exposure compared to uncoated cement. In contrast, higher additive concentrations resulted in increased cracking and poor moisture resistance. Overall, the findings suggest that agar-based seaweed and kelp coatings are promising renewable alternatives for cement protection, although further optimization is needed for long-term practical application.
This study evaluated agar-based coatings incorporating seaweed and kelp biomass as sustainable protective materials for cement surfaces. Agar, seaweed, kelp, and gelatin were initially assessed individually for gelation and film-forming behavior, followed by testing of combined formulations for structural integrity, surface cracking, UV resistance, and water absorption. Agar was the only individual material that formed a stable hydrogel, and agar-based mixtures with seaweed or kelp successfully formed solid coating films, whereas gelatin-based mixtures remained liquid. Among the tested formulations, the 1.5 g agar–seaweed and 1.5 g agar–kelp coatings showed the best performance, forming more uniform films with fewer cracks, reduced water absorption, and reduced microcrack formation after UV exposure compared to uncoated cement. In contrast, higher additive concentrations resulted in increased cracking and poor moisture resistance. Overall, the findings suggest that agar-based seaweed and kelp coatings are promising renewable alternatives for cement protection, although further optimization is needed for long-term practical application.
