Composite Panel Blast Testing Summary
Three blast tests were performed on the composite stud wall panels of the ProtectiFlex technology at the Stone-OBL blast testing site located in Deschutes County, Oregon near 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. Stone-OBL Test Fixture with Steel Frame and Plate System
The blast‐tested composite stud wall panels were nominally 8‐ft (2440‐mm) tall by 4‐ft (1220‐mm) wide and each consisted of vertical cold‐formed steel studs embedded in a layer of ProtectiFlex (Ballistic‐Blast Mix Design). The blast testing and assessment compared the standoffs and wall weights used in the test program to the CCSDs and wall weights given in Table 1.
The explosive charges used in the testing program were equivalent to car and truck bomb threats with different standoff distances for each test. The performance of the composite stud wall panels during these tests were recorded using sensors and normal and high-speed cameras. The ranges of gauge readings recorded for positive phase pressure and impulse are presented in Table 2, along with summary of the blast performance. Figure 2, Figure 3 and Figure 4 show photographs of the ProtectiFlex composite stud wall panel following Test 1, Test 2 and Test 3, respectively.
Table 1. Conventional Construction Standoff Distances per UFC 4‐010‐01 for W I Explosive Threat
|Conventional Wall Construction Type||CCSD for LLOP Non-Load Bearing
|Minimum Weight per Unit Area
|ProtectiFlex Composite Stud Wall System||40 (12)||10 (50)|
|Metal Studs w/ Brick Veneer||207 (63)||45* (220)|
|Metal Studs /w EIFS||420 (128)||11** (54)|
|Reinforced Concrete||26 (8)||85** (415)|
|Reinforced Masonry||30 (9)||57** (280)|
|Unreinforced Masonry||125 (38)||47** 230|
* - Value includes 44psf(215kg/m2 for weight of brick veneer.
** - Value includes 10psf (50 kg/m2 for weight of EIFS or other insulating materials.
Blast Test Results
Table 2. Blast Test Results Summary
|Test||Specimen||Charge Standoff||Peak Pressure||Positive Phase Impulse||Post Test Notes|
|No observable permanent damage or permanent deflection. Response categorized as Superficial Damage/HLOP.|
| 96-109 psi-ms
|Cracking of ProtectiFlex layer noted on interior face at interface with rightmost vertical stud. Minor hairline cracking noted elsewhere. Minor observed deformation and indentations to the vertical and horizontal steel stud components. Response categorized as Moderate Damage/MLOP.|
| 153-178 psi-ms
|Extensive cracking of ProtectiFlex layer noted on interior face near interface with three rightmost vertical studs. Cracking also visible on exterior face. A small amount of ProtectiFlex debris projected inward up to 5 feet (1.5m). Minor observed deformation and indentations to the vertical and horizontal steel stud components. Response categorized as Heavy Damage/LLOP.|
Figure 2. Post‐Test Photos of Test 1
Figure 3. Post‐Test Photos of Test 2
Figure 4. Post‐Test Photos of Test 3
Figure 5. ProtectiFlex Composite Panel Blast Test - External View Real Time
Figure 6. ProtectiFlex Composite Panel Blast Test - Internal View Real Time
Excluding the insulating materials, these weight reductions are 55% and 28%, respectively. This significant weight reduction for the ProtectiFlex composite stud wall system can be advantageous in construction to meet non‐blast design requirements. In any case, the tested performance of the composite stud wall system is a significant improvement over conventional unreinforced masonry or metal stud construction, which would require a standoff of well over 100 feet (30.5 m) to achieve an LLOP.