Experimental behaviors of CFRP cloth strengthened buried arch structure subjected to subsurface localized explosion

• Blast responses of CFRP strengthened buried arch was revealed by experiments.
• CFRP strips restrict structural crack formation, concrete spalling and steel fracture.
• Debonding is the main failure mode of CFRP strengthened buried arch.
• Rigidity and load carrying are improved by CFRP strips.

To improve the anti-blast ability of buried arches, carbon fiber reinforced polymers (CFRPs) were applied to strengthen the concrete arch. A structural model experiment was carried out on a buried scaled-down reinforced-concrete arch structure subjected to underground close-in explosions. The aim of the experiment is to provide believable results of strengthening effects through the dynamic loads, deflections, strains and failure modes. To achieve this objective, blast experiments were carried out under 0.6, 3, 6 and 17.4 kg TNT charges, respectively. Distribution laws of the applied dynamic loads, strains and the failure modes of the arch were revealed. Different from the spalling, steel fracture and structural macro-cracks, CFRP strengthened arch renders failure styles as micro-crack belts, composite delamination and structural macro-cracks. Concrete spalling and steel fracture are restricted. Formation of macro-cracks is delayed. Rigidity and load carrying ability are improved.