When exposed to temperatures that are progressively and rapidly raised, large dimension fibre cement boards tend to crack. This occurrence is analysed and explained for a specific issue of asymmetric growth of a curvilinear crack in high temperatures. This phenomenon occurred while performing Single Burning Item (SBI) experiments at fire loads which are higher than those used in countries of the European Union, which better reflect fire events that may occur in high-rise buildings. In such conditions, fibre cement boards crack, allowing the fire to reach the thermal insulating material which then combusts, thereby helping to spread the conflagration to upper floors. This experiment investigated the temperatures at which fibre cement boards crack, and why. Thermal analysis methods and thermogravimetric experiments were conducted on the fibre boards, followed by X-ray phase analysis investigations. During this phase, X-ray structural analysis was performed while the fibre cement was exposed to temperatures of 1000 °C. The article also presents ongoing change results when heating only composite fibre-cement board materials; phase changes that take place in high temperatures are discussed.

中文翻译：

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使用热重分析确定高温火灾条件对纤维水泥板的影响

当暴露于逐渐快速升高的温度时，大尺寸纤维水泥板往往会开裂。针对高温下曲线裂纹的不对称增长这一特定问题，对这种情况进行了分析和解释。这种现象是在比欧盟国家使用的火灾负荷更高的情况下进行单一燃烧项目（SBI）实验时发生的，这更好地反映了高层建筑可能发生的火灾事件。在这种情况下，纤维水泥板开裂，使火到达隔热材料，然后燃烧，从而有助于将大火蔓延到上层。该实验研究了纤维水泥板开裂的温度以及原因。对纤维板进行了热分析方法和热重实验，随后进行 X 射线相分析研究。在此阶段，将纤维水泥暴露在 1000 °C 的温度下进行 X 射线结构分析。该文章还介绍了仅加热复合纤维水泥板材料时的持续变化结果；讨论了在高温下发生的相变。