Scaling of Thermal Damage of Cementitious Materials: Application to Refractory Concrete.

The aim of this study is to investigate and to model the damage mechanisms of concrete after exposure to high temperature. The multiphase Digital Concrete Model and the damage model, MODEV, implemented on finite-element software SYMPHONIE, were used simultaneously to model the thermal damage of concrete exposed to high temperature. In order to validate the thermal damage model, an experimental investigation was carried out. The measurement of the mechanical characteristics of 5 cementitious materials, cement paste, mortar, ordinary concrete and 2 HPC concretes were performed by 3-point bending tests after heating/cooling cycles at 393, 523 and 673 degrees K. The experimental tests on the 3 different cementitious materials compared to numerical simulation are presented for temperatures up to 673 degrees K. After the validation of the models, several applications have been investigated, such as fire resistance of refractory concretes.