Effect Of Biological Coating (Crassostrea Gigas) On Marine Concrete: Enhanced Durability And Mechanisms

This paper presents an interdisciplinary research into investigating the effect of a Crassostrea gigas (C. gigas) coating on the durability of marine concrete and the related mechanisms in depth. Thirtytwo concrete specimens at four mix proportions were prepared and exposed to the tidal zone of Xiaokouzi Bay in the Yellow Sea for 450 days. The coefficient of water absorption, charge passed, carbonation depth, and microstructure of the concrete, as well as the strength of the bond between the C. gigas and the concrete, were determined. The results demonstrate that the presence of the C. gigas coating can reduce the water absorption of concrete, and enhance the resistance of concrete to chloride penetration and carbonation. Moreover, these positive effects are more evident in concrete without mineral admixtures. The enhanced durability benefits from the combined effect of the C. gigas shell and its organized adhesive layer. The C. gigas coating is a natural anti-corrosion protection of marine concrete with ecological significance. (C) 2021 Elsevier Ltd. All rights reserved.