ABSTRACT
Abstract The long term performance of cementitious materials is usually addressed from the point of view of physical and chemical processes that may occur over time and may lead to deleterious effects. Such influences can be considered as a material property and they can be evaluated by studying small specimens in the laboratory or in exposure sites. As a result, when new materials are evaluated for long term performance the tendency is to identify whether such physical and chemical processes may occur. However, attention should be given also to another type of effect which is associated with internal stresses that may develop in the material. Such stresses can be the result of autogenous shrinkage or environmentally induced shrinkage, which may induce relatively high stresses when the material is used to produce components which are restrained during their service. The present paper highlights such influences in two advanced cementitious materials: high quality concretes and fiber reinforced thin sheet cementitious composites. The magnitude of the stresses that might be developed and the need to deal with this problem combining the material and overall design points of view are highlighted. Key words: internal stresses, autogenous shrinkage, cracking, restrain, high strength concrete, fiber reinforced cement.
