A New Intermediate-scale Fire Test for Evaluating Building Material Flammability

Abstract

A new intermediate-scale fire test has been developed as a screening tool to evaluate wall and ceiling assemblies for material flammability. The scale of the test is large enough for the tested materials to reveal their behavior in a full-scale fire, but still small enough to provide substantial cost savings compared to 25-ft and 50-ft corner tests used for decades to evaluate wall/ceiling panels and other building materials. The test consists of parallel panels of the material assemblies being evaluated, which are each 1.07 m wide and 4.9 m high and separated by 0.53 m. A 360 kW propane sand burner is used as the ignition source. The parallel panel test is conducted under a 5-MW fire products collector to measure fire heat release rate (HRR). Materials used during development of the new test include various thicknesses of: polyvinylchloride, fire retardant plywood, fiberglass-reinforced melamine and panels with metal facings over foamed polyurethane, polystyrene, and polyisocyanurate. Comparisons with the 25-ft and 50-ft corner tests indicate that fire propagation behavior in the corner tests correlates well with the maximum HRR in the parallel panel test as follows: fire will not propagate to the end of the test array in the 25-ft corner test with combustible wall panels and a noncombustible ceiling if the HRR in the parallel panel test is <1100 kW; fire will not reach the top of the test array in the 50-ft corner test if the HRR in the parallel panel test is less than 830 kW; fire propagation will not reach the ends of the horizontal ceiling in the 25-ft corner test with both combustible wall and ceiling panels if the HRR in the parallel panel test is <830 kW.

Fire performance evaluation of cladding wall assemblies using the 16‐ft high parallel panel test method of ANSI/FM 4880

“…In these tests, a wood fire source imposes a 110 kW/m 2 heat flux to the base of walls oriented in a corner arrangement, and the extent of fire propagation is measured during the test using thermocouples. [30][31][32][33] Although the corner fire tests simulate realistic scenarios, the tests are expensive to run and require extensive amounts of materials and preparation time.…”

“…Since the 1990s, several research studies were conducted to develop a new test that would correlate with the corner tests and be comparatively cost-effective. [31][32][33][34][35][36][37][38][39] In these studies, walls were tested in a parallel panel test (PPT) configuration; the PPT configuration involves two parallel panel wall specimens mounted at a specific separation. A sand burner is located at their base to provide a desired fire exposure to simulate heat fluxes relevant to corner fire tests.…”

“…36 Several iterations have been made to the design of the PPT configuration over the years, and their results are detailed in the literature. 31,33,37,38 In 2007, Nam 38 standardized a final 16 ft (4.9 m) high PPT (16-ft PPT) configuration as shown in Figures 3A,B; the test configuration consists of two 16 ft (4.9 m) high and 3.5 ft (1.1 m) wide wall panels parallelly mounted at a 1.75 ft (0.5 m) separation. A well-controlled propane sand burner (dimensions 1.1 m × 0.5 m × 0.3 m) provides a 360 kW fire exposure that results in a 110 kW/m 2 peak heat flux to the lower portion of both wall panels, 33,40 which is the same as the heat flux to wall panels in the corner fire tests.…”

“…31,33,37,38 In 2007, Nam 38 standardized a final 16 ft (4.9 m) high PPT (16-ft PPT) configuration as shown in Figures 3A,B; the test configuration consists of two 16 ft (4.9 m) high and 3.5 ft (1.1 m) wide wall panels parallelly mounted at a 1.75 ft (0.5 m) separation. A well-controlled propane sand burner (dimensions 1.1 m × 0.5 m × 0.3 m) provides a 360 kW fire exposure that results in a 110 kW/m 2 peak heat flux to the lower portion of both wall panels, 33,40 which is the same as the heat flux to wall panels in the corner fire tests. 30 A detailed experimental study 33 has shown that the peak chemical heat release rate (HRR) from 16-ft PPTs correlates well with the flame spread extent of the corner fire tests, and this global parameter can be used as a reliable measurement and objective pass-fail criterion of the test.…”

Energy Balance Models of Downward Combustion of Parallel Thin Solid Fuels and Comparison to Experiments

“…One of the intermediate-scale fire tests consists of two parallel samples with a gas burner at the surface (Alpert, 2003;de Ris and Orloff, 2005). This parallel panel configuration has been recently employed as a tool for predicting costly full-scale fire tests (e.g., Nam and Bill, 2009). In the parallel panel test, samples are burned upward in order to reproduce the most hazardous configuration, and many efforts have been devoted to properly simulate such an upward flame spread (see, e.g., Wasan et al, 2011).…”