PRESTRESSED CONCRETE BEAMS UNDER FULL SCALE BLAST TEST

The use of prestressed concrete structural elements in protective structures is not recommended in the literature although, for large structures such as ammunition storage magazines, using prestressed concrete tends to be more economical. A research program has been initiated to evaluate the behavior of precast prestressed concrete beams in an accidental explosion scenario. A 3 by 10.4 meters roof segment, containing two precast prestressed beams, with a 10 meter free span, was tested in a full scale blast test. The segment was covered with earth and located at about 100 meters from an 82 ton explosive bare charge, which was detonated as a part of an international geophysical test. Free field blast pressures and the roof mid span deflections were recorded. High-speed video camera was used to track the internal mid span deflections and the dynamic response. Extensive cracking and tendon failure, without structural collapse, were observed. The results were analyzed and compared to single-degree-of-freedom calculations.