Title: Durability of Concrete Exposed to Marine Environment--A Fresh Look

Author(s): P. K. Mehta

Publication: Symposium Paper

Volume: 109

Issue:

Appears on pages(s): 1-30

Keywords: concrete construction; concrete durability; corrosion; deterioration; fatigue (materials); marine atmospheres; mix proportioning; permeability; reinforced concrete; reinforcing steels; Materials Research

DOI: 10.14359/1899

Date: 8/1/1988

Abstract:
From recently reported case histories of concrete deterioration in seawater, the author has taken a fresh look at the conclusion presented on this subject at the last CANMET/ACI Conference on the Performance of Concrete in Marine Environment. It is confirmed again that between seawater and the constituents of hydrated cement paste, harmful chemical reactions such as carbonation, sulfate attack, and magnesium ion attack can be limited to the surface when well known measures to assure low permeability of concrete have been put into practice. From the standpoint of permeability of concrete, the topics discussed in detail include selection of materials and mixture specifications, concreting practice, and control of in-service cracking due to thermal gradients, frost attack, improper loading conditions, fatigue, and corrosion of the embedded steel in concrete. The ACI and FIP Recommended Practice for offshore concrete structures and recent field experience from the North Sea are compared, to highlight the issues that are relevant to long-time durability of concrete. Since high-strength concretes (50 to 70 MPa) containing water-reducing and mineral admixtures are relatively impermeable, in the opinion of the author they offer an excellent solution to the problem of durability of concrete in seawater environment.