1. Was the BRB designed and tested by a blast expert?
The science of blast-resistant building (BRB) design is still considered new, and only a small group of experts have tested their designs. Make sure your BRB design has been taken off the drawing board and successfully blast-tested under the supervision of a well credentialed engineer.
2. Are blast test reports specific and conclusive?
There are many interpretations of the term blast-tested (see question five), but a successfully blast-tested building has the proven ability to actually save lives. Pay special attention to psi ratings when you review blast test reports because different applications call for different specifications. A laboratory BRB placed next to a blowdown stack should carry a higher rating, such as 8 psi, while a guard shack placed at the perimeter of your facility may only need a 3- to 5-psi rating.
3. Was the BRB blast-tested for nonstructural/ structural components?
If a structure survives a blast but its interior walls, lights or other fixtures create shrapnel, the risk of casualties is still high. Always ask BRB vendors to provide data and rationale for nonstructural items including wall and ceiling finishes, light fixtures, plumbing fixtures, cabinets, placement of open shelving (should be no higher than 40 inches above the floor) and placement of any intake points (should be less than 3 feet above ground level).
4. Can the following information be provided?
- Was the BRB tested dynamically rather than statically?
- Was the BRB tested in a free field environment?
- Was a P-I (pressure-impulse) curve generated to show the BRB's response over a wide range of blast loading?
These items are too technical to cover in the context of this article but should be on your list of discussions to initiate with any BRB vendor. Our engineering department can even address these issues with you too.
5. Does the BRB's response level demonstrate its capability to save lives?
As mentioned in question two, interpretation of ratings is everything. A BRB vendor can claim its product has been blast-tested (and maybe it has) but if closer examination of test data demonstrates a high-response result, this is not the BRB you want protecting your personnel. Response level ratings have been established by the American Society of Civil Engineers to predict the extent of repair resources needed after an explosion. Here's the key: high response equals high damage, so it's crucial to study the response level table, then take a very close look at any BRB's response rating for a given psi (as proven through actual blast testing).
With continued research and product development, previously hazy areas of BRB engineering are quickly coming into focus. When you go shopping for a BRB, it's important to ask solid questions and expect solid answers. What it really boils down to is finding a vendor that's committed to doing the right thing, and this commitment will be visible in the vendor's documentation.