ABSTRACT
Cement mortars and concretes have been used extensively in their present form since the beginning of the nineteenth century. There is no need to set out here their history or to describe their properties and applied technologies, because nearly every year several excellent books are published on these subjects. However, there is perhaps at present a new phase of development of Portland cement-based materials, stimulated by the following factors:
New types of these materials have appeared and are available. They • satisfy new performance exigencies but they also create new requirements for their use and demands on staff competence. New theoretical and experimental methods are available, derived from • various technical fields, but mainly from the field of high strength advanced composites. The behaviour of concrete-like materials is more correctly understood • and these materials are better used in practice if a modern approach is applied to them as well as to the composite materials. Durability is considered the main property of structures and this expec-• tation imposes new requirements on cement-based materials. Concretes should satisfy various requirements that in the past century • were not imposed or that did not have the importance they have now; this concerns various ecological aspects, because sustainability is a key worldwide concern.
