Abstract To explore the protective effect of reinforced concrete (RC) slabs strengthened with different protective layers of materials (polyurea, steel plate, foam aluminum, and ultrahigh‐performance concrete UHPC) under contact explosion, a study was carried out on the failure mode, damage evolution process and midspan displacement of the protected RC slabs. Furthermore, evaluation indicators such as energy dissipation sharing ratio, kinetic energy conversion rate, and damage grade classification are adopted to assess the protective effectiveness of the protected RC slabs under different protection schemes. The research results show that, under contact explosion loads, strengthening RC slabs with different material protective layers can effectively reduce the level of destruction to RC slabs. Among all the protective layers, the one with the aluminum foam protective layer reinforced on its blast‐facing side exhibited the highest energy dissipation ratio, with the energy dissipation share rate and kinetic energy conversion rate reaching 27.6% and 33.5%, respectively. The protective effects of energy absorption and wave attenuation are greatest when a RC slab is strengthened with a polyurea protective layer on the back explosion surface, with the energy dissipation sharing ratio and kinetic energy conversion rate being 2.1% and 57.6%, respectively. Additionally, damage indices were used to classify the damage grades of different protection schemes. Among them, the damage index of the blast‐facing surface reinforced with an aluminum foam protective layer was 0.242, which was 57.2% lower than that of the unprotected scheme. The damage grade changed from severe damage to moderate damage. The damage index of the RC slab strengthened with a polyurea protective layer on the back‐blast surface was 0.29, representing a 48.7% decrease compared with that of the unprotected scheme. This significantly improved the destruction level of the RC slab (moderate damage). In summary, it is recommended that aluminum foam be used as the protective layer for the blast‐facing side and that polyurea be used as the protective layer for the back‐blast side. These research results can serve as a foundation for the application of different material protective layers in the field of anti‐blast protection for RC structures.
Cao et al. (Fri,) studied this question.