Performance evaluations of PSC panel from impact-induced fire loading

Abstract

Since the World Trade Center and Pentagon attacks in 2001, terror bombings, military attacks and man-made disasters have frequently induced impacts, explosions and fire on civil infrastructure. However, research into the structural behaviour of major prestressed concrete (PSC) infrastructure (e.g. bridges, tunnels, prestressed concrete containment vessels (PCCVs) and liquefied natural gas (LNG) storage tanks) under extreme loading is limited due to the difficulties involved in conducting studies on instantaneous extreme loading scenarios. In particular, research into possible secondary fire scenarios on concrete structures after a bomb explosion or accidental collision has not been performed, while most previous research is related to extreme isolated loading scenarios on structures. Due to a great deal of public concern and anxiety over potential collision accidents on major infrastructure, a study on PSC structural behaviour from an impact-induced fire scenario was undertaken. Bi-directional PSC panels of size 1400 × 1000 × 300 mm subjected to a 430 kN prestressing force using unbonded prestressing thread bars were tested for an impact–fire loading scenario. More specifically, using a drop weight test facility in Korea, tests were performed using a 14 kN impactor with drop heights of 10 m and 3·5 m to apply impact loading to the PSC panels. RABT fire loading was then applied to the impact-damaged PSC panels. After the impact–fire test, a three-point line loading test was performed on various undamaged and damaged reinforced concrete and PSC panels to evaluate and compare their residual bending strengths. The results obtained from the study can be used as basic data for the protective design of PSC panel structures such as PCCVs and LNG tanks for real impact accident scenarios.