Title: Long-Term Performance of Portland and Blended Cement Concretes Under Marine Conditions

Author(s): H. Roper. V. Sirivatnanaon, and D. Baweja

Publication: Symposium Paper

Volume: 145

Issue:

Appears on pages(s): 331-352

Keywords: binders (materials); blended cements; concretes; corrosion; durability; fly ash; marine atmospheres; slags; specifications; Materials Research

DOI: 10.14359/4550

Date: 5/1/1994

Abstract:
Specifications relating to concrete durability have been emphasized in many recent codes of practice governing the design of concrete structures. Typical examples of this trend are noted in Australian Standard AS 3600, British Standard BS 8110, and a "Guide to Durable Concrete," reported by ACI Committee 201. Apart from the requirements of higher strength grades to insure required minimum water-cement ratios for aggressive environment exposures, some advantages offered by the use of blended cements have been recognized in these documents. The use of blended slag and fly ash cements in increasing worldwide and specific information on the long-term performance of such concretes in high-chloride environments is needed. Paper presents data on the long-term corrosion characteristics in high-chloride environments of reinforcement within a series of concretes individually incorporating a high C 3A ordinary portland cement, a low C 3A cement, a slag blended cement, and an ASTM Class F fly ash blended cement. The concrete performance has been assessed using electrochemical monitoring of corrosion of the embedded reinforcement by potentiodynamic anodic polarization and concrete resistivity. Comments are made regarding current North American, British, and Australian specifications for concrete under marine service conditions. From the data presented, the specification for long-term durability of concrete for marine conditions could be based on concrete resistivity with a suggested limit of around 5000 ohm cm at 28 days.