Characterising fundamental fire protection performance of intumescent coating under realistic fire conditions

英国70%以上的商业建筑是钢框架结构，膨胀涂料目前占钢结构防火市场的50%以上。然而，膨胀涂料在实际火灾条件下的防火性能尚不清楚，因为对其防火性能的评估是基于所谓的标准耐火试验，在该试验中，火灾暴露与实际火灾条件无关。膨胀涂料是一种反应性材料，其性能高度依赖于火灾暴露类型，因此使用标准的耐火试验来评估其性能是不成立的。这一问题变得尖锐起来，因为消防安全设计正在从标准火灾条件下的指令性设计转向考虑实际火灾条件的基于性能的设计。此外，在基于性能的设计下，现在正在消除钢结构防火方面的大部分冗余，以降低建筑成本。因此，重要的是关键的防火材料在现实的火灾条件下表现出预期的性能。性能化消防安全设计是一种技术进步。为了帮助建筑业安全地利用这项新技术的进步，拟议的研究将开发一种合理的方法来表征膨胀涂料在现实火灾条件下的防火性能。这项拟议的研究将涉及在锥形量热计和炉膛中对一系列加热条件下的膨胀型涂料产品进行广泛的测试，英国两家最大的膨胀型涂料制造商将提供相关的行业建议、免费测试样品和TGA测试结果。将进行分析以建立一种程序来提取膨胀涂料的下列关键防火特性：化学反应动力学常数(根据TGA数据)、最大膨胀速率(根据可用于膨胀的持续时间)、空隙体积和等效空隙大小(根据质量损失、膨胀速率和热传递分析)。这项拟议的研究旨在验证这样一种假设，即从一小组火灾试验中提取的上述关键特性可以应用于其他火灾条件。一些初步工作已经在一个由提倡者监督的博士项目中完成，以证明所提议的方法的可行性。这项研究将通过调查不同火灾条件下的不同膨胀涂料产品来考察该方法的广泛适用性，并将开发一种可靠的协议来可靠地提取现实火灾条件下膨胀涂料的关键防火性能特性。

Over 70% of commercial buildings in the UK are steel framed and intumescent coating now accounts for more than 50% of the steel structure fire protection market. However, the fire protection properties of intumescent coating under realistic fire conditions are not known because assessment of their fire protection performance is based on the so-called standard fire resistance tests in which the fire exposure bears no relation to realistic fire conditions. Intumescent coating is a reactive material and its properties are highly dependent on the fire exposure type so using the standard fire resistance test to assess its performance is not valid. This problem has become acute because fire safety design is now moving away from prescriptive design under the standard fire condition to performance based design which allows for realistic fire conditions. In addition, under performance based design, much of the redundancy in fire protection to steel structures is now being removed to reduce construction cost. It is therefore important that the critical fire protection materials perform as intended under realistic fire conditions. Performance based fire safety design is a technology advance. In order to help the construction industry to safetly exploit advances in this new technology, the proposed research will develop a rational method of characterising the fire protection performance of intumescent coating under realistic fire conditions. The proposed research will involve extensive testing of a number of intumescent coating products exposed to a range of heating conditions under a cone calorimeter and in furnace and will be carried out with substantial contributions from the UK's two largest intumescent coating manufacturers who will provide relevant industrial advice, free test samples and TGA test results. Analysis will be performed to establish a procedure to extract the following key fire protection properties of intumescent coating: chemical reaction kinetics constants (from TGA data), maximum rate of expansion (from an understanding of the duration of time available for intumescing), void volume and equivalent void size (from mass loss, rate of expansion and heat transfer analysis). This proposed research aims to validate the hypothesis that the above key properties extracted from a small set of fire tests can be applied to other fire conditions. Some preliminary work has already been done in a PhD project supervised by the proposers to demonstrate the feasibility of the proposed methodology. The proposed research will investigate wide applicability of the method, by investigating different intumescent coating products under different fire conditions and will develop a robust protocol to reliably extract the key fire protection performance properties of intumescent coating under realistic fire conditions.