Polyurea elastomer for enhancing blast resistance of structures: Recent advances and challenges ahead

As an excellent anti-blast material, polyurea (PU) has been widely used in the reinforcement of masonry walls, RC structures, steel structures, and composite materials. The advances in the static and dynamic mechanical properties, dynamic constitutive models, and applications of PU in the field of blast resistance are reviewed. Although results have indicated the potential of PU in anti-blast reinforcement, the underlying mechanisms are not fully understood. Widely recognized mechanisms include shock wave induced ordering and hydrogen bonding changes in the hard domain, viscoelastic energy dissipation, and impedance matching between PU and matrix. Potential problems in the field of PU anti-blast transformation are summarized, and corresponding solutions are proposed.