主管:中华人民共和国应急管理部
主办:应急管理部天津消防研究所
ISSN 1009-0029  CN 12-1311/TU

消防科学与技术 ›› 2024, Vol. 43 ›› Issue (4): 487-491.

• • 上一篇    下一篇

自然老化对古建筑马尾松燃烧行为和力学性能的影响

龙邈天, 易亮, 颜龙, 郑佳欣   

  1. (中南大学 防灾科学与安全技术研究所,湖南 长沙 410075)
  • 出版日期:2024-04-15 发布日期:2024-04-15
  • 作者简介:龙邈天(1998- ),男,中南大学土木工程学院消防工程系硕士研究生,主要从事防火阻燃材料研究,湖南省长沙市天心区韶山南路22号,410075。
  • 基金资助:
    国家自然科学基金项目(52276143);湖南省重点研发计划项目(2021SK2054)

The effect of natural aging on the combustion and mechanical properties of ancient architectural Pinus massoniana

Long Miaotian, Yi Liang, Yan Long, Zheng Jiaxin   

  1. (Institute of Disaster Prevention Science and Safety Technology, Central South University, Hunan Changsha 410075, China)
  • Online:2024-04-15 Published:2024-04-15

摘要: 选取距今约170年的清代木结构建筑屋内和屋外马尾松为研究对象,系统分析自然老化对马尾松微观结构、燃烧行为及力学性能的影响规律。结果表明,自然老化作用会显著破坏松木的细胞结构,其中屋内松木服役过程中易因虫蚁蛀蚀和真菌寄生而出现明显的表面虫洞现象,而屋外松木服役过程中易受紫外线作用而发生更显著的内部有机成分降解。相比于内部有机成分降解,表面虫洞现象会更大程度恶化松木的力学性能,其中屋外清代松木的抗拉强度和抗弯强度较现代松木下降了27.4%和10.8%,而屋内清代松木则分别下降了48.2%和31.6%。燃烧性能分析表明,自然老化作用削弱了木材的燃烧强度和热稳定性,其中屋内清代松木和屋外清代松木的峰值热释放速率较现代松木分别降低了8.4%和15.4%,初始分解温度(T5%)较现代松木分别降低了19.2、10.1 ℃。相比于屋外清代松木,屋内清代松木具有更低的T5%值与更高的CO2与CO产生速率,这主要与屋内清代松木的细胞结构破坏程度较大有关,表现出较低的热稳定性和较强的火灾烟气毒性。

关键词: 马尾松, 自然老化, 微观结构, 燃烧行为, 力学性能

Abstract: The Pinus massoniana inside and outside the Qing Dynasty wooden building from approximately 170 years ago was taken as the research object to systematically analyzes the effects and regulations of natural aging on the microstructure, combustion behavior and mechanical properties of the Pinus massoniana . The results show that natural aging can significantly damage the cellular structure of the pine, where indoor pine is susceptible to significant surface wormholes due to insect infestation and fungal parasitism during service, while outdoor pine is susceptible to more significant degradation of internal organic constituents due to UV light. Compared to the degradation of internal organic components, the surface wormholes can deteriorate the mechanical properties of the pine to a greater extent. The tensile and bending strengths of outdoor Qing Dynasty pine are lower than those of modern pine by 34.1% and 34.7%, respectively, while those of indoor Qing Dynasty pine are reduced by 48.2% and 31.6%, respectively. Combustion performance analysis reveals that the natural aging effect weakens the combustion strength and thermal stability of the wood, with the peak heat release rate (PHRR) being reduced by 8.4% and 15.4%, and the initial decomposition temperature (T5%) being reduced by 19.2 and 10.1 ℃, for the indoor Qing Dynasty pine and outdoor Qing Dynasty pine, respectively, compared to the modern pine. In addition, compared with the outdoor Qing Dynasty pine, the indoor Qing Dynasty pine has lower T5% and higher CO2 and CO production rate, which is mainly related to the greater destruction of the cellular structure of indoor Qing Dynasty pine, thereby indicating that the indoor Qing Dynasty pine has lower thermal stability and stronger fire smoke toxicity.

Key words: Pinus massoniana, natural aging, microstructure, combustion behavior, mechanical properties