Skin Effect of Chloride Ingress in Marine Concrete: A Review on the Convection Zone


The formation mechanism on the convection zone (“skin effect”) of chloride ingress are explored systematically by contrasting concretes in marine atmospheric, splash, tidal, and submerged zones. The depth of convection zone, Δx, and the maximum chloride concentration, Cmax, are two important indicators for estimating the degree of action of the skin effect. Influences of various factors on the skin effect are analyzed, including environmental conditions, mixture proportion, exposure time, and construction method. Statistics of the Δx and Cmax were extracted from field test data in the literatures. Influence of skin effect on the apparent surface chloride concentration (Cs) and diffusion coefficient (Da) was analyzed. Results show that the skin effects of concrete in atmospheric, tidal, splash and submerged zones are different, and it is highlighted that the convection zone exists even in submerged zone. The skin effect of concrete significantly impacts the fitting values of Cs and Da. Effective processing approaches can account for the skin effects of the concrete during durability design.


Materials Science and Engineering

Second Department

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

INSPIRE - University Transportation Center

Keywords and Phrases

Convection zone; Diffusion coefficient; Marine environment; Maximum chloride concentration; Skin effect; Surface chloride concentration

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2020 Elsevier, All rights reserved.

Publication Date

30 Nov 2020