ABSTRACT
Modern concrete, of both normal and high strength, shows high cracking tendency at very early ages, i.e. before thermal cracking. There are cases when cracks develop in high performance concrete slabs in spite of careful curing. Cracking takes one always by surprise, which points out our fragmentary knowledge of the mechanisms of cracking. This paper has the following purposes: to give some examples of possible causes of cracking, to adopt an adequate criterion for cracking, to discuss the possibilities of predicting cracking and to point out the cases for which prediction could be possible.
