Successful Fire Tests Add Steel Frame Listings to Fire Resistance Directory
Two successful full-scale fire tests conducted by the American Iron and Steel Institute and the American Institute of Steel Construction at Underwriters Laboratories provide insight for construction professionals struggling to decide whether to specify restrained or unrestrained fire protection thicknesses for structural steel-framed buildings. The answer is that the required fire protection will be the same, at least for the floor construction described in the new U.L. Design No. D982.
AISI and AISC conducted tests of two unrestrained structural steel-framed floor specimens with 4.5” of normal weight concrete over steel deck supported by a W-shape beam. The first test was conducted on January 8, 2013 and ran for 2 hours and 32 minutes before the loading mechanism reached its limit. The second test was held on March 13, 2013 and ran for 2 hours and 29 minutes before the limit was reached. Both tests exceeded expectations.