The purpose of this symposium was to acquaint engineers and scientists interested in hydraulic cements and concrete with analytical procedures used in learning more about: the nature of cement minerals, the nature of hydrated-cement paste, and the causes when hydrated-cement paste fails to perform satisfactorily. The recent trend in cement and concrete technology has been to modify portland cement and concrete by using materials that, when interground in very small amounts with the cement clinker, assist in the grinding operation, improve the storability of the cement, or improve some of the properties of the concrete; and when added in very small quantities to the concrete during mixing improve some of its properties. For the most part these additions and admixtures are organic materials, and a considerable amount of research has been directed toward the development of analytical techniques for identifying these materials in cement and concrete, and for determining the amounts present. These papers show the diverse nature of the problems of determining compositions of the minerals formed during the manufacture of cement, the nature of reactions of the cement minerals with water and with each other during the setting and hardening of the cement paste, and the type and amounts of additions and admixtures that should be used in the manufacture of the cement and in the preparation of the concrete. If this volume serves to inform the engineer about the analytical procedures available to him in determining the causes of unsatisfactory performance of a cement or concrete in the field, and if it stimulates other investigators to do research in this field, it will have served its aims.