Snozzi, L.Caballero, A.Molinari, J. F.2011-11-022011-11-022011-11-02201110.1016/j.cemconres.2011.06.016https://infoscience.epfl.ch/handle/20.500.14299/72166WOS:000295438600006We investigate the dynamic behavior of concrete in relation to its composition within a computational framework (FEM). Concrete is modeled using a meso-mechanical approach in which aggregates and mortar are represented explicitly. Both continuum phases are considered to behave elastically, while nucleation, coalescence and propagation of cracks are modeled using the cohesive-element approach. In order to understand the loading-rate sensitivity of concrete, we simulate direct tensile-tests for strain rates ranging 1–1000 s−1. We investigate the influence of aggregate properties (internal ordering, size distribution and toughness) on peak strength and dissipated fracture energy. We show that a rate independent constitutive law captures the general increase of peak strength with strain rate. However, a phenomenological rate-dependent cohesive law is needed to obtain a better agreement with experiments. Furthermore, at low rates, peak strength is sensitive to the inclusions' toughness, while the matrix dominates the mechanical behavior at high rates.Finite element analysisTensile propertiesMicromechanicsConcreteDependent Cohesive ModelBrittle MaterialsStrain-RateCrack-PropagationUniaxial TensionLattice ModelDamageEnergyStrengthImpacttext::journal::journal article::research article