A heat-transfer rate inducing system (H-TRIS) test method

A novel fire testing method, named the Heat-Transfer Rate Inducing System (H-TRIS), is presented and described in this paper. The method directly controls the thermal boundary conditions imposed on a test specimen by controlling a specified time-history of incident radiant heat flux at its exposed surface. Accounting for the absorptivity and thermal losses at the exposed surface of the test specimen, H-TRIS can be programmed to control the net heat flux at the exposed surface; thus controlling the in-depth time dependent temperature distributions within the test specimen. H-TRIS can be used for imposing a wide range of time-histories of incident radiant heat flux (e.g. constant, linear, stepped), or in-depth time dependent temperature distributions (i.e. specified thermal gradients). Notably, this enables simulation of thermal boundary conditions experienced by materials or structures exposed to any source of heat – during a conventional fire test (e.g. standard furnace test), a large-scale fire test, a real fire, or some other thermal boundary conditions calculated using a fire model (e.g. zone or computational fluid dynamics model). H-TRIS enables complementary experimental studies with excellent repeatability at comparatively low economic and temporal costs relative to traditional furnace test methods, thus permitting multiple repeat tests and statistical studies of response to heating. Application of H-TRIS within a research project studying heat-induced concrete spalling is briefly presented and discussed, to illustrate the significance and novelty of the new fire testing method.