Experimental and numerical study of CFRP protective RC piers under contact explosion

In the wake of the event of September 2001, the increasing terrorist attacks have been a destabilizing threat around the world. Public infrastructures, such as tall buildings and traffic facilities, have become attractive bombing targets for terrorists. Crucial bridges subjected to great destruction from bomb attacks can contribute to casualties, property loss and interruption of the transportation system. Bridge piers are the main axial bearing components that are common in bridge construction, and it can readily suffer damage under blast loading. Therefore, it should be necessary to explore protective measures for reinforced concrete (RC) piers to resist blast loading. In this paper, carbon fibre reinforced polymer (CFRP) is chosen to protect RC piers under contact explosion. Five piers, consisting of two unprotected piers and three CFRP protective piers, were constructed and the explosion testing was conducted in the field. Additionally, finite element models of CFRP protective piers were built, considering the contact between concrete and CFRP as well as the anisotropy of CFRP composite material. The models were calculated using the Arbitrary Lagrange Euler (ALE) algorithm and validated by experimental acceleration as well as damage extent. Then, the damage development and CFRP protective effect for RC piers were further analysed. Finally, all specimens experienced local failure under contact explosion and the simulative models were proved accurate for depth analysis.