The book "Properties of Concrete," first published in 1963, has been internationally recognized as the definitive reference work on the subject, both for professionals and for engineering students. The fifth edition has been updated to reflect developments in concrete technology over the last decade, while maintaining the original aim: to provide reliable, comprehensive, and practical information on the properties and use of concrete, as well as the selection of mix proportions, all based on scientific observations and the author's extensive engineering experience. Emphasis is given to understanding concrete behavior and its relation to the physical and chemical phenomena involved in its performance in service, to achieve the best possible concrete construction. Additionally, the scientific basis of the provided information is valuable for planning research and interpreting test results.