ABSTRACT
The occurrence and control of cracks at an early age of concrete are an important practical problem. Especially in massive concrete members cracks are predominantly caused by thermal stresses. These stresses arise due to the heat of hydration and its flow to the surrounding air, to the subsoil or to older concrete members connected with the newly cast con crete, etc.. Drying shrinkage only negligibly contributes to early age cracks in the first weeks after casting. For HPC chemical shrinkage is im portant.
