C. B. Porter, R. W. Gilmore,F. H. Johnson, Lewis H. Tuthill, and Byram W. Steele
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Report on conditions affecting durability of concrete structures, and discussion of design modifications and changes in construction and maintenance’ procedures to prolong their useful life. Surveys of structures of various ages and an evaluation of factors affecting their durability. Brief report of research on testing and developing water-proofing materials. A brief discussion of the factors that control durability of concrete pavements. Structural performance and durability are defined and their relationship to each other and to water-cement ratio brought out. The role of air entrainment in improving the durability of concrete pavements, particularly under the attack of chloride salts used for ice removal, is discussed and present thinking on the subject summarized. The necessity of controlling volume change and providing impermeability in mass concrete hydraulic structures contributes to the problems of durability. Mix design, placement methods, use of admixtures and other measures to increase the serviceability of such work are considered. The need for impermeable concrete is stressed as the primary requirement for lasting durability of mass hydraulic structures. Research in all phases of concrete mix and design is recommended as the answer to the need for a method of evaluating permeability in regard to its permanent effect on the durability of concrete thus establishing a realistic approach to specifying cement content of concrete mixtures in which strength is of secondary importance.