e numerical simulation of concrete dams subjected to earthquake loading requires realistic material laws which take into account seismic loading conditions. Dynamic tests were performed in order to examine the effect of initially applied compressive loading on material properties of a dam concrete at high tensile deformation rates. The test results show that no important fracture property is reduced at high deformation rates; the tensile strength and the specific fracture energy GF show a high rate sensitivity. However, dynamic compressive pre-loading leads to a reduction of the fracture properties at both quasi-static and high deformation rates.