Title: Marine Exposure of High-Strength Lightweight Concrete

Author(s): G.C. Hoff

Publication: Symposium Paper

Volume: 209

Issue:

Appears on pages(s): 29-46

Keywords: freezing and thawing; high-strength; lightweight aggregates; lightweight concrete; marine exposure

DOI: 10.14359/12492

Date: 9/26/2002

Abstract:
An extensive laboratory program was initiated in the early 1980's to develop high-strength lightweight concrete for use in offshore oil and gas structures in severe marine environments. From the results of that development program, four mixtures were chosen to be evaluated under field conditions. Large prisms (305 by 305 by 914mm) of each mixture were placed in the tidal zone at the U.S. Army Corps of Engineers Severe Weather Exposure Station on the border between Canada and the United States. The mixtures used an expanded slate aggregate from the USA and a pelletized clay aggregate from Japan. All mixtures contained silica fume and had total binder content from 494 to 556 kg/cu m with water-binder ratios of 0.28 by mass. The concrete density varied from 1800 to 1990 kg/cu m, with 90-day strength from 60 to 73 MPa depending on the mixture. The prisms under-went annual visual and non-destructive evaluations. After 10-years exposure in the tidal zone, the prisms were removed to the laboratory where they were examined for strength, robustness and chloride ion penetration. This paper reports the results of the test program. In general, the overall performance looks very good.