Cement durability program, long-term field exposure of concrete columns
Roshore, E. C.
Technical reportAbstract: Fifty-two portland cements were collected from 47 cement mills distributed throughout the United States for the purpose of developing information about the manufacture, composition, and durability of these cements. After an extensive laboratory test program (previously reported), concrete columns were fabricated using these cements, and these columns were exposed at outdoor tidal weathering stations at Treat Island, Maine, and St. Augustine, Florida. Variables in the exposures were exposure location, type of cement, and aggregate type. The outdoor exposures were carried on for periods up to 30 years. Concrete columns made with untreated cements exhibited very low resistance to the tidal freezing and thav1ing at Treat Island. Concrete columns made with treated cements exhibited good to extraordinary durability. The treated cements contained a saponifiable material such as resin, tallow, or oil, and the resultant air-entraining property of these cements accounts for their good durability in the tidal freezing-and-thawing exposure. The durability of concrete columns at Treat Island with respect to the aggregates used is in the following order (maximum to minimum durability): traprock, gravel or dolomite, limestone. The results of these Treat Island exposures indicate the necessity for providing an appropriate air-void system in concrete which is to be exposed to freezing and thawing while saturated. This air-void system can be provided by the use of an air-entraining cement (as in these cases) or by use of an air-entraining agent in the concrete mixture. Concrete columns made with 48 cements (44 untreated cements and 4 treated cements) exhibited satisfactory resistance to tidal weathering at St. Augustine, Florida. Concrete columns made with three cements (two treated cements and one untreated cement) performed unsatisfactorily in the St. Augustine exposure. These cements had a high tricalcium aluminate (C3A) content (more than 13 percent), high is believed to be responsible for their poor performance. The St. Augustine exposure indicates the necessity of specifying maximum limits for the tricalcium aluminate content of a cement which is to be used in concrete which is to be exposed to a moist high-sulfate environment.
Concrete Laboratory (U.S.)Engineer Research and Development Center (U.S.)
Concrete columns; Concrete durability; Concrete tests; Portland cements
Technical report (U.S. Army Engineer Waterways Experiment Station) ; C-72-2.
Approved for public release; distribution is unlimited.