In this paper a test method to determine the deformation capacity and the resistance-deformation curve of blast-loaded slabs is described. This method was developed at TNO-PML. The method has been used to determine the ultimate deformation capacity of some simply supported reinforced concrete slabs in order to increase the knowledge of this parameter. The influence of the following parameters on the dynamic deformation capacity has been studied: the thickness of the slab, the amount of bending reinforcement and the diameter of the bending reinforcement. Preliminary results have been obtained.