Evaluation of the internal blast resistance of a bi-directionally prestressed concrete tubular structure according to ANFO explosive charge weight

When an extreme internal loading is applied to prestressed concrete (PSC) structures, serious property damage and human casualties may occur. However, the existing designs for PSC structures such as prestressed concrete containment vessels (PCCVs) do not include features to protect the structure from forces such as explosive blasts. Therefore, we evaluated the internal blast-resistance of PSC structures using blast tests on bi-directionally prestressed tubular concrete members. The goal of the study was to examine structural behavior data after an internal detonation. Explosive charges (ammonium nitrate – fuel oil; ANFO) were detonated at the center of the mid-span of the concrete tube with a standoff distance of 1000 mm. The data acquired included blast pressure, deflection, strain, crack pattern, and prestressing loss. The data were used to calculate the internal blast charge weight required to cause a PCCV to fail and to calibrate a simulation program to be used commercially for internal blast simulations at real scale structure.