Blast Protection
As Promat DURAWALL® is often used in high risk areas such as data centres where the results of fire or blast bear additional and more serious consequences, Promat DURAWALL® has been the subject of stringent blast testing at the government’s Health & Safety Laboratory, an agency of the Health & Safety Executive. Details of this agency are publicly available at www.hsl.gov.uk.
Blast Test Method
Two Promat DURAWALL® walls were exposed to a total of six explosive-charge tests.
The first test wall was constructed with five fixings per panel-end into a structural steel frame, stitching screws at the panel joints and high-modulus mastic at the perimeter. This sample was exposed to three explosive-charge blasts.
The second test wall was constructed using only three fixings per panel-end into the frame, only one stitching screw mid-point at the panel joints and no high-modulus mastic. This was subjected to three explosive charge blasts, for the last two of which, the mid-point stitching screw was removed.
The three explosive charges to which each test piece was subjected, were 100g, 100g and 200g of a military plastic explosive with a TNT equivalence of approximately 1.35. The charge was placed at 2.5m from the test wall.
Results
The two sets of trials have produced very similar results. Pressures encountered by the wall structure have been approximately 80kN/m2 (shots 1 and 2) and 130kN/m2 (shot 3). The structure has performed well. While some delamination appears to have taken place the structure was intact at the end of the sets of three tests.
1kN/m2 = 0.01 bar = 0.145 psi
1 bar = 100kN/m2 = 14.5 psi
1 psi = 6.89 kN/m2 = 0.068 bar
Conclusions
Promat DURAWALL® performs strongly in the event of blast conditions. The laminate nature of the system means a significantly reduced risk of collapse and of flying debris on the side of the wall opposite to the explosion risk. The self-evident protection afforded by the system to sensitive areas such as data halls could therefore be significant should such an event occur.
For the purposes of comparison of Promat DURAWALL® with other materials, it is the understanding of Promat UK that other structures, depending on their specification, may be subject to failure by pressures of the following amounts:
| Concrete block walls |
13.8 kN/m2 - 20.7 kN/m2 |
| Concrete walls |
68.9 kN/m2 |
Promat DURAWALL® not only withstood pressures of up to approximately 130kN/m2, it underwent three separate tests and did so without suffering any significant damage.