International Concrete Abstracts Portal

Title: Marine Corrosion Behavior of Reinforced Concrete Exposed at Tokyo Bay

Author(s): M. Makita, Y. Mori, and K. Katawaki

Publication: Special Publication

Volume: 65

Issue:

Appears on pages(s): 271-290

Keywords: chlorides; cover; corrosion; cracking (fracturing); crack width and spacing; electrical resistance; exposure; marine atmospheres; reinforced concrete; reinforcing steels; sea water; specimens; thickness; water-cement ratio.

Date: 8/1/1980

Abstract:
Reinforced concrete test specimens of 23 kinds were exposed on the sea in Tokyo Bay for about 1000 days, and corrosion of the reinforcement in the concrete was measured. As the result, the following were disclosed: 1) Corrosion of the reinforcement in concrete is affected greatly by both the cover thickness and water- cement ratio; 2) Test specimens exposed from seawater into air had no corrosion produced in the submerged portion but had corrosion produced at a particular height above the sea surface; 3) Test specimens exposed in air above the sea surface had irregular partial corrosion produced; 4) Electric resistance of theconcrete where corrosion occurred was low, and so was the natural potential of the reinforcing steel, and the corrosion occurred at valleys of the distributions of electric resistance and natural potential; and 5) From the foregoing, partial corrosion of the reinforcing steel in concrete is due to macro-corrosive current flow as the potential distribution in the reinforcing steel had peaks and valleys produced.