Title: Evaluation and Control of Steel Corrosion in Offshore Concrete Structures

Author(s): Todd E. Gjorv and Oystein Vennesland

Publication: Symposium Paper

Volume: 100

Issue:

Appears on pages(s): 1575-1602

Keywords: cathodic protection; chlorides; concrete durability; diffusion; corrosion resistance; cracking (fracturing); electrical resistance; evaluation; marine atmospheres; offshore structures; oxygen; research; reinforcing steels; seawater; General

DOI: 10.14359/3805

Date: 4/1/1987

Abstract:
To provide a better basis for evaluation and control of steel corrosion in offshore concrete structures, a comprehensive research program was carried out a few years ago at the Norwegian Institute of Technology. In this paper, the most important findings of this program are briefly presented. For corrosion of embedded steel the importance of considering the concrete as an electrolytic system is emphasized. If the passivity of the embedded steel is broken either by chloride penetration or by carbonation, the electrical resistivity and the availability of dissolved oxygen are the main controlling factors for corrosion to occur. In the present program basic information on these electrolytic factors was obtained for typical environmental conditions prevailing in the oceans. The effect of cracks and cathodic protection was further investigated. A system for field control and corrosion monitoring was also developed.