Summary: | Polyurea can effectively improve the anti-blast performance of normal reinforced concrete (NRC) panels. However, there are very limited studies on the damage assessment of polyurea strengthening NRC (PU-NRC) panels after near-field explosion. In this paper, a high-fidelity finite element (FE) model of PU-NRC panel was developed and validated by the results from near-field explosion and static loading tests. Subsequently, the deterioration of the bearing capacity was selected as a damage criterion to assess the damage of the PU-NRC panel after explosion. The impacts of polyurea thickness, panel thickness, compressive strength of concrete and longitudial reinforcement ratio on the damage levels of the PU-NRC panel were further discussed. Finally, the empirical formulas of P-I diagram were developed to assess the damage level of the PU-NRC panel after varied blast loads. The results showed that spraying polyurea can improve the stiffness of NRC panel under blast load. In addition, the closer the standoff distance, the better the strengthening effectiveness of polyurea. Increasing polyurea thickness was more effective to increase the value of overpressure asymptote, and spraying polyurea had little contribution to improve the shear resistance of the NRC panel. This research has significant implications for practitioners and scholars in protective engineering.
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