Optimizing a Design Solution for Blast-Resistant Modular (BRM) Construction

In the current BRM market the primary modules tend to be either robust steel modules which meet the rigorous 8 psi long duration load, per the guidelines and recommended practices in ASCE Design of Blast Resistant Buildings in Petrochemical Facilities and API RP 752/753 Compliant Modular Blast-Resistant Buildings, or relatively weak wood stud modules which can only resist loads on the order of 0.6-0.9 psi.

To address this concern, Stone Protective Solutions, LLC (SPS) has developed a patent-pending blast-resistant Extreme-Woodlam panel technology can be applied to the manufacturing and/or upgrades of BRM units that need to meet safety design requirements from accidental explosions or security Anti-Terrorism design requirements from bomb attacks.  SPS has designed BRMs that combine steel and SPS’s proprietary Woodlam Panels which are able to not only meet the 8 psi or the 0.9 psi loads, but which can also meet 2 psi, 4 psi, or 6 psi long duration loads, thereby reducing costs by allowing our clients to use BRMs which aren’t too strong and aren’t too weak, but that are just right.

SPS has tasked Stone-OBL, LLC to blast test the patent-pending blast-resistant Extreme-Woodlam panel technology. Two tests were performed at the Stone-OBL blast testing site located in Deschutes County, Oregon approximately 30 miles (48 km) east of Bend, Oregon. An existing reinforced concrete reaction structure was supplemented with a rigid steel frame and plate system to accommodate the test panel, as shown in Figure 1.

Figure 1 –Blast-Resistant Extreme-Woodlam Panel within Stone-OBL Concrete Reaction Structure

The explosive charges used in the testing program were equivalent to car and truck bomb threats with different standoff for each test. The performance of the slab during these tests were recorded using sensors, normal speed and high speed cameras. The ranges of gauge readings recorded for positive phase pressure and impulse are presented in Table 1.  Figure 2 and Figure 3 show photographs of the panel following Test 1 and Test 2, respectively.

Table 1 – Reflected Blast Pressure Gauge Readings

Figure 2 – Post-Test 1 Exterior (left) and Interior (right) Photographs

Figure 3 – Post-Test 2 Exterior (left) and Interior (right) Photographs

The maximum displacement of the Extreme-Woodlam panel did not exceed 0.4 inches (10 mm) for either test within the first 150 ms of recorded response.  Moreover, no damage and permanent panel deformation was observed in either case during post-test inspection (i.e., the panel returned to its original pre-test position resulting in an elastic response).  As such, Extreme-Woodlam panels with a similar through-thickness lay-up and span can likely sustain significantly higher blast loads than those tested prior to achieving permanent deformation. The panels can potentially take even higher loads for applications where permanent panel deformation is acceptable (e.g., where panels are subjected to a one-time blast event and only need to sustain capacity to allow for personnel egress).

For more information, please visit us at www.stoneprotective.com or contact us at info@StoneProtectiveSolutions.com