During the hardening process of concrete energy is released as heat. Due to temperature differences the concrete will tend to expand or contract and there is a risk of cracking of the concrete due to restrained volume changes from the temperature and shrinkage. When casting takes place upon an existing concrete structure, the relative stiffness will have an influence on whether or not cracks are formed. On basis of the heat of hydration in the hardening concrete and the thermal boundary condition, the temperature distribution as a function of time can be calculated in a finite element analysis. In order to determine the stress situation, it is necessary to describe the modulus of elasticity and creep as function of maturity or degree of reaction. This paper presents material models that are capable of describing both the heat production and the stress development during the hydration process of concrete.
