FRACTURE MECHANICS OF CONCRETE: AN APERQU OF BASIC CONCEPTS AND MODELS
Originated in 1921 by Griffith, fracture mechanics is a theory of failure which was for a long time applied only to metallic structures and ceramics. Concrete ^ structures, on the other hand, have been successfully designed and built without any use of fracture mechanics, even though their failure process involves crack propagation. However, the proper type of fracture mechanics, which takes into account the growth of distributed cracking and its localization into major fractures, did not begin to emerge until about 1980. During the 1980’s, however, such a type of fracture mechanics has emerged, as a result of a surge of research activity. Fracture specialists became convinced that introduction of fracture mechanics into the design of concrete structures, both reinforced and plain, is inevitable and will eventually bring about a revolution comparable to the introduction of plastic limit
analysis, which occurred during 1930-1970. It will significantly improve structural safety and economy. It will be particularly important for safe exploitation of the capabilities of high-strength and fiber-reinforced concretes. It might even make possible new structural forms, similarly as the research of creep and shrinkage made possible the development of prestressed concrete.