建筑外墙防裂网对XPS燃烧行为及火灾危险性影响

Effect of Anti-Cracking Mesh on Combustion Behaviour and Fire Risk of XPS

为了探究建筑外墙防裂网与挤塑聚苯乙烯保温泡沫板(XPS)复合层的火灾危险性,揭示防裂网对XPS火灾性能影响规律,采用热重分析仪和锥型量热仪对XPS热解特性及三种典型防裂网复合层燃烧特性参数进行了系统测定,并分析计算各复合层火灾危险综合指数。研究表明,不同升温速率下,环境温度超350℃时XPS均处于不稳定状态,升温速率越小,热解越完全;抹灰钢丝和玄武岩纤维这两种材料的双层防裂网复合结构均促进了XPS的燃烧,而单层防裂网复合结构则降低了XPS的火灾危险性;玻璃纤维单层防裂网复合结构的火灾危险性高于双层防裂网复合结构,且玻璃纤维网复合结构增大了XPS的火灾危险性。因此,在复合保温板制作或外墙保温设计时可优先考虑单层玄武岩纤维网格布或单层抹灰钢丝网与XPS进行复合;尽可能避免使用玻璃纤维网格布与XPS进行复合,若无法避免,则可以考虑使用双层玻璃纤维网复合进而降低火灾危险性。研究结论填补了不同材料防裂网对XPS火灾危险性影响方面的不足,为建筑外墙保温面层及新型保温板复合材料的选择提供参考依据。

To investigate the fire hazards of the composite layer of anti-cracking mesh and extruded polystyrene insulation foam board(XPS),and to reveal the influence of anti-cracking mesh on the fire performance of XPS,the thermogravimetric analyser and cone calorimeter were used to systematically determine the pyrolysis characteristics of XPS and the combustion characteristics of three typical anti-cracking mesh composite layers,and to analyse and calculate the comprehensive fire hazard index of each composite layer.The experimentals shows that,XPS is in an unstable state at ambient temperatures above 350℃at different heating rates,and the smaller the heating rate,the more complete the pyrolysis.The double-layer anti-fracture mesh composite structure of plastered steel wire and basalt fibre both promote the combustion of XPS,while the single-layer anti-fracture mesh composite struc‐ture reduces the fire hazard of XPS.The fire hazard of the single-layer anti-fracture mesh composite structure of glass fibre is higher than that of the double-layer anti-fracture mesh composite structure.The fire hazard of the single-layer glass fibre composite struc‐ture is higher than that of the double-layer anti-cracking mesh composite structure,and the glass fibre mesh composite structure increases the fire hazard of XPS.Therefore,the use of single-layer basalt fibre mesh or single-layer plastered steel wire mesh with XPS can be considered a priority when making composite insulation panels or designing external wall insulation.The use of glass fibre mesh with XPS can be avoided as far as possible,and if this cannot be avoided,then double-layer glass fibre mesh can be considered to reduce the fire hazard.The findings of the study fill the gap in the impact of different materials of anti-cracking mesh on the fire risk of XPS and provide a reference basis for the selection of new insulation panels and composite materials for building facades.