Blast experiments on reinforced concrete structures are often limited to small structures and therefore simple shock waves. Such experiments are carried out at the Bundesanstalt für Materialforschung und -prüfung (BAM) and the structural response is investigated using several measuring methods. Complex load scenarios that occur as a result of reflection of the shock wave in larger structures are harder to realize in practice. Numerical simulations for the propagation of the shock wave and the structural response can therefore be an alternative method for the investigation of blast loads on complex structures. For the simulation of concrete under impact and blast loads, several local constitutive models exist that are formulated as plasticity models with softening taken into account by introducing a scalar damage field. Local damage models however often lead to mesh-dependent results which do not converge with mesh refinement. In order to achieve meaningful predictions from numerical experiments, independence from the mesh is needed. In this contribution, the Johnson-Holmquist model (JH2) for brittle damage [2] has been implemented for the free open source software FEniCSx and is investigated in a high strain rate benchmark simulation. Mesh-convergence analyses show that displacements as well as the dissipated plastic energy do not converge with mesh-refinement. Following the gradient-enhancement approach by [1], a gradient-enhanced JH2 model which can be efficiently solved with explicit solvers is introduced and its advantages over the local models are discussed. Since many damage models for concrete share the damage mechanism of the JH2 model, the application of the regularization methods to more complex material models, like the RHT model [3], is also discussed. Advantages of a gradient-enhanced formulation to simulate dynamic strength increase of concrete, as suggested in [1], is discussed as well. [1] U. Häußler-Combe and M. Kitzig. Modeling of concrete behavior under high strain rates with inertially retarded damage. en. In: International Journal of Impact Engineering 36.9, 2009. [2] Gordon R. Johnson and Tim J. Holmquist. An improved computational constitutive model for brittle materials. In: AIP Conference Proceedings 309.1, 1994. [3] Christoph Grunwald, Benjamin Schaufelberger, Alexander Stolz, Werner Riedel, and Thomas Borrvall. A general concrete model in hydrocodes: Verification and validation of the Riedel–Hiermaier–Thoma model in LS-D