Field test and numerical modelling of RC slabs at different scaled distances with two types of external reinforcement

This work deals with the response of eight reinforced concrete (RC) slabs, made at full-scale, some of them with the addition of externally bonded fibre reinforced polymer (FRP). The reinforcements were placed in all cases on the face opposite to the explosive detonation. Three scaled distances have been used from 0.83 m/kg1/3, in one test with no extra reinforcement; four tests were made with a scaled distance of 0.42 m/kg1/3: one without extra reinforcement, two with carbon fibre reinforcement (CFRP) and one with the E-glass fibre reinforcement (GFRP); finally, 0.21 m/kg1/3, in three trials, one without extra reinforcement, one with carbon fibre reinforcement and one with the E-GFRP. The first slab, used for calibration of the numerical models, was instrumented with pressure and acceleration sensors. For the validation of the other seven slabs, the damage surfaces on both sides of the slabs are used. In terms of numerical simulation performed with LS-DYNA, several models covering different solutions such as smooth particle hydrodynamics (SPH) or load blast enhanced have been performed for the description of the explosive, as well as the use of CSCM material models for concrete to analyse the best available solutions. The steel was modelled with the piecewise linear plasticity material, while the material laminated composite fabric was used for the FRP. Reinforcement with CFRP resulted in a generally reduced damage area on both surfaces. All models show a good correlation, including nonspherical charges made with SPH models, with the test results when comparing them with respect to acceleration and surface damage. SPH models work well for the high and medium scaled distance, but not so good for the shorter scaled distance.