Standard fire resistance tests have been used in the design of structural building elements for more than a century. Originally developed to provide comparative measures of the level of fire safety of noncombustible products and elements, the recent resurgence in engineered timber construction raises important questions regarding the suitability of standard fire resistance tests for combustible structural elements. Three standard fire resistance floor tests (5.9 m × 3.9 m in plan), one on a concrete slab and two on cross‐laminated timber (CLT) slabs, were undertaken to explore some of the relevant issues. The fuel consumption rate within the furnace was recorded during these tests, and the energy supplied from this was determined. An external fuel supply (from natural gas supplied to the furnace) equating to approximately 3 MW was recorded throughout the concrete test, whereas this was about 1.25 MW throughout the CLT tests. The total heat release rate was calculated using carbon dioxide generation calorimetry; this yielded values of approximately 1.75 MW during the CLT tests (ie, an additional energy contribution of approximately 0.5 MW from the timber). This demonstrates that considerably more energy input (by about 1.25 MW) was needed to heat the system when the test sample was noncombustible. A further series of six large‐scale compartment fire experiments (6 m × 4 m × 2.52 m) was undertaken to further explore comparative performance of combustible versus noncombustible construction when the external fuel load is kept constant and is governed by more realistic compartment fire dynamics. For a fuel‐controlled case, the peak temperatures in the compartment with an unprotected CLT ceiling were approximately 200°C higher than in the compartments with a concrete ceiling, whereas for a ventilation‐controlled case, the compartment with a CLT slab ceiling displayed a burning duration that increased by approximately 15 minutes. Potential implications for standard fire resistance testing of combustible specimens are discussed.

中文翻译：

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可燃板和不燃板的耐火性测试中的比较能量分​​析

超过一个世纪以来，标准耐火测试已用于结构建筑构件的设计中。最初是为比较不燃产品和元件的防火安全水平而开发的，最近工程木结构的兴起使人们对标准的耐燃性结构耐火性试验的适用性提出了重要的疑问。为了探讨一些相关问题，进行了三项标准耐火地板测试（计划中为5.9 m×3.9 m），一项在混凝土板上，另一项在交叉层压木材（CLT）板上。在这些测试中记录了炉内的燃料消耗率，并确定了由此提供的能量。在整个混凝土试验中，记录到的外部燃料供应（来自供应至炉的天然气）约为3 MW，而在整个CLT试验中，外部燃料供应约为1.25 MW。使用二氧化碳发生量热法计算总放热率；在CLT测试中，这产生了大约1.75 MW的值（即，木材产生了大约0.5 MW的额外能量贡献）。这表明当测试样品不可燃时，需要更多的能量输入（约1.25 MW）来加热系统。进一步进行了六个大型隔室射击实验（6 m×4 m×2）。当外部燃料负载保持恒定并由更现实的车厢火灾动力学控制时，进行了52 m）的试验，以进一步探索可燃与不可燃结构的比较性能。对于燃料控制的情况，具有未保护的CLT顶棚的车厢的峰值温度比具有混凝土顶棚的车厢中的峰值温度高约200°C，而对于通风控制的情况，具有CLT平板车顶的车厢的峰值温度显示为燃烧持续时间增加了大约15分钟。讨论了可燃样品的标准耐火性测试的潜在含义。而对于通风控制的情况，带有CLT平板天花板的隔室的燃烧持续时间增加了大约15分钟。讨论了可燃样品的标准耐火性测试的潜在含义。而对于通风控制的情况，带有CLT平板天花板的隔室的燃烧持续时间增加了大约15分钟。讨论了可燃样品的标准耐火性测试的潜在含义。