Influence of the softening curve in the fracture patterns of concrete slabs subjected to blast

•Numerical analysis of an original series of tests made by the authors.•Shear and bending modes are the principal failure modes of the slabs tested.•Shape of the softening curves is causes dissimilarities in the crack patterns.•Results supported by simulations with own developed constitutive model for concrete.

Reinforced concrete elements subjected to blast may present shear failure modes different to those expected under static loading. Shear failure under impulsive loading is caused by the fracture of concrete under tensile stresses, a topic which has not been thoroughly assessed under high strain rates. This research sheds light on this issue, through the experimental results provided by the authors and an own-developed constitutive model for the simulation of concrete under blast loading, based on the Cohesive Crack Model. Findings point out the importance of the shape of the softening curve of concrete in the development of different failure modes.