Full-scale experimental testing of the blast resistance of HPFRC and UHPFRC bridge decks

Because of the current geopolitical situation, research on improving the resistance of the civil and transport infrastructure to blast or impact loads has gained considerable attention in recent years. This paper presents the results of full-scale blast experiments designed to characterize the resistance of steel-fiber-reinforced concrete full-scale bridge decks subjected to near-field blast loading, and its dependence on the material properties of the concrete. The blast performance of reinforced concrete specimens increases with added high-performance steel fibers. An increase in fiber content and in compressive strength up to ultrahigh-performance fiber concrete (UHPFRC) further enhances its blast performance. An attempt was made to further increase the blast resistance of a concrete structure with the use of a basalt mesh. The UHPFRC specimen with a basalt mesh experienced a greater extent of internal damage than a regular UHPFRC specimen. However, the basalt mesh inserted into the concrete cover at the soffit of the UHPFRC specimen improved its blast performance, as expressed by the area of spalling and the volume of debris. This phenomenon was studied numerically, and it was proved that it is caused by the internal rebound of the shock wave, which causes a local increase in the stresses inside the specimen. The heterogeneity of the specimens, which is increased by an internal reinforcement or by a basalt mesh, converts the blast damage due to internal rebounds into layer delamination. The delamination of the concrete specimen can be very effective in dissipating the energy of the blast wave.