The discrete element model proposed in this paper addresses the macroscopic behavior of concrete taking into account the presence of free water in pores, thanks to a new interaction law between spherical discrete elements (DE). When concrete structures are subjected to a severe loading, e.g., an impact, material exhibits high triaxial compressive stresses which are highly influenced by the saturation ratio. In this new constitutive model, cracking and compaction are modeled at the interaction level between DEs and free water effects are taken into account by introducing a dependency between the water saturation ratio and the inelastic deformation due to the pore closure. The present numerical model has been implemented in the Yet Another Dynamic Engine code in order to deal with extreme loading situations leading to stress states characterized by a high mean stress level.