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Summary: A new test methodology was developed to investigate the response of walls, partitions, and in‐wall systems exposed to real fires. The apparatus includes a 3.5 m long, 2.3 m wide, and 2.3 m high fire compartment within a standard sea container. A wall specimen measuring up to 1.8 m wide, 1.8 m tall, and 0.3 m deep is mounted in a steel frame at one end of the fire compartment. Fire exposures to the wall specimen evolve over time depending on the fuel load and ventilation configuration. Gas temperatures and heat flux were characterized for five different fuel and ventilation configurations. Peak exposures ranged from 30 to 75 kW/m2 for about 20 minutes. Five additional tests were conducted using a single fuel and ventilation configuration to assess the repeatability of the test methodology. It was found that a 19.3 minute growth period occurred plateauing at a ceiling temperature of 708°C for 8.4 minutes, on average. Compartment gas temperatures were found to be repeatable, having a sample standard deviation less than 32°C for symmetric data. Repeatability improved when account was taken for the rapid fire growth inflection point. The utility of the approach for studying fire performance of building elements was demonstrated. [ABSTRACT FROM AUTHOR]

An important step in calibrating a cone calorimeter apparatus is the determination of gas delay times. Gas concentration measurements must be made simultaneously in time with the main combustion events and processes (i.e., ignition, changes in mass loss rate, smoke production, and observed phenomena) to produce accurate results from the test. The calibration methodology prescribed in ASTM E1354-14e1 does not specify direct measurement of the transit time of gases through the apparatus or the response time of the individual analyzers, instead estimating total delay time by relating the thermal lag in the stack thermocouple to the transient response of the gas analyzers. Other methods to account for gas delay times are used in practice, leading to varying opinions on the method that is most suitable for oxygen consumption calorimetry. Furthermore, studies have shown that analyzer delay times are not consistent test-to-test, but depend on both the characteristics of the gas analyzer and sampling system (gas transit time) and the rates of production or consumption of gaseous species during a particular test (analyzer response time). In the present work, a methodology was proposed for measuring analyzer delay times by injecting a gas mixture of known concentration into the cone calorimeter exhaust stream. Delay times were computed using various methods, including ASTM E1354 and gas injection, and were evaluated with a series of cone calorimeter tests on various materials. Gas delay times determined by the ASTM E1354 method were found to produce inconsistent results for the cone calorimeter used in this study; results were significantly improved when alternative criteria were applied to the method. The square wave method was found to produce very good results for specimens with heat release rates greater than 3kW; however, delay times in carbon monoxide production were not well represented. The gas injection method was found to produce excellent results, closely tracking oxygen consumption, carbon monoxide production, and carbon dioxide production in time, and as a result, the derived heat release rate coincided with observed events. [ABSTRACT FROM AUTHOR]