Title: Concrete Weathering at Treat Island, Maine

Author(s): Katharine Mather

Publication: Symposium Paper

Volume: 65

Issue:

Appears on pages(s): 101-112

Keywords: aggregates; alkali-aggregate reactions; concretes; freeze-thaw durability; high temperature; low temperature; marine atmospheres; sea water; sulfate attack; sulfate resistance; weathering.

DOI: 10.14359/6349

Date: 8/1/1980

Abstract:
Subsequent to the investigation of the correlation between laboratory accelerated freezing and thawing and weathering at Treat Island, Maine, reported in 1953 (1) there have been some developments especially in the field of sulfate resistance of concrete that serve to further elucidate the findings then reported. There have also been many contributions to improve understanding of the causes and nature of the many different kinds of chemical reactions that can and do occur between aggregates of all kinds and the surrounding cement paste, so long as the exposure of the concrete is such as to keep it moist--as is the case at Treat Island, Maine. This paper suggests that there is a complex series of interactions among the constituents of cements, aggregates, and seawater not previously appreciated. Sulfate susceptibility of blended cements is becoming better understood and the use of certain blended cements promises to provide a useful alternative to moderately or highly sulfate-resisting portland cements. It also now is clear that no aggregate particle in portland-cement concrete long stored in an environment of moistness and moisture movement can be regarded as completely inert. What is becoming clear is that aggregates differ greatly in the nature, degree, and consequences of their chemical activity.