Blast resistant glazing tests

Recent attacks at home and abroad have increased concems about blast-resistant glazings. The Glass Research and Testing Laboratory (GRTL) conducted fíve blast tests. This thesis describes the procedure for five fiill-scale blast-resistant glazing tests and the air blast pressure-time history analysis. One free field pressure transducer and three reflected pressure transducers collected 40960 points per second of air blast pressure-time data from the blast tests. These data facilitated the prediction of peak air blast pressures and positive phase impulses acting on the blast-resistant test specimen. They indicated that air blast pressure exerted an equivalent GS A Level D air blast pressure loading on the test specimen.

The blast-resistant glazing consisted of an insulating glass unit fabricated with laminated glass. The insulating glass units consisted of two VA in. (6.0 mm) heat sfrengthened laminated glass lites with a 0.030 in. (0.76 mm) polyvinyl butyral (PVB) interlayer sealing a Vi in. (13 mm) air space. The design blast consisted of 250 Ibs of ANFO at a standoff distance of 75 ft. The GRTL staff determined the test specimen adequately resisted a GSA Level D air blast loading of 10 psi peak air blast pressure and 80 psi-msec positive phase impulse. Although many of the laminated glass units fractured under the blast loading, the units remained in the glass frame, they maintained closure of their fenestration, and the witness panel located twelve inches behind the test specimen remained free of flying or falling glass shard.