Behavior of Plain Concrete High Strength, High Density Concrete.

Any sound concrete, in sections of sufficient thickness, can be used to construct a satisfactory biological shield. When space permits, conventional concrete is the most economical, satisfactory shield against radiation. However, when space is a consideration, high density concrete can be used for shielding. Most high density concrete for shielding has been made with naturally occurring iron ores, titaniferous iron ores, "hydrous iron ores, and barite. Although structural strength is an important factor in high density concrete, workability and density have been the major factors previously studied. This investigation showed that high strength concrete can be made using materials that provide high density, and that high density concrete can be made using proportions that ensure high strength. When high strength and high density are both desired, they can be attained by a direct combination of the standard practices developed for attaining each condition separately. Concrete made as part of this study using magnetite aggregate or ilmenite aggregate having a hardened unit weight of about 230 lb per cu ft had a compressive strength of 9000 psi at 7 days and I 1,000 psi at 28 days. [ABSTRACT FROM AUTHOR]