With the growing risk of fungal degradation in timber-framed structures from significant moisture intrusion events due to climate change, it is increasingly critical to develop mechanistic relationships between fungal degradation mechanisms and the strength of untreated wood components. While extensive work has been performed characterizing wood decay, no study has yet addressed the effects of Meruliporia incrassata on untreated Southern Yellow Pine. This seeks to address this knowledge gap by evaluating the effects of the common brown rot fungus on an ubiquitous building material in the southeast United States – Southern Yellow Pine. Properties of Southern Yellow Pine were evaluated at seven decay stages over the course of 12 weeks of exposure to M. incrassata. Changes in physical properties – mass, density, and moisture content – were measured at each stage. Changes in stiffness were characterized via ultrasonic pulse velocity testing, and thermogravimetric analysis was utilized to assess compositional changes. The study found rapid and significant losses in stiffness at decay stages as early as four-weeks. Hemicellulose and cellulose degradation occurred steadily throughout the decay period. These results can be utilized to develop a stronger understanding of the mechanical behavior of timber-framed structures in the United States degraded by brown rot.

中文翻译：

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Merulliporia incrassata 对南方黄松的机械、物理和成分影响

由于气候变化导致的严重湿气侵入事件，木结构结构中真菌降解的风险越来越大，因此建立真菌降解机制与未经处理的木材构件强度之间的机械关系变得越来越重要。虽然已经进行了大量的工作来表征木材腐烂，但尚未有研究解决木材腐烂的影响灰树花在未经处理的南方黄松上。该项目旨在通过评估常见的褐腐真菌对美国东南部无处不在的建筑材料——南黄松的影响来解决这一知识差距。在 12 周暴露​​于环境中的过程中，对南方黄松在七个腐烂阶段的特性进行了评估。斑叶海棠。在每个阶段测量物理特性的变化——质量、密度和水分含量。通过超声波脉冲速度测试来表征刚度的变化，并利用热重分析来评估成分变化。研究发现，早在四个星期的腐烂阶段，刚度就出现了快速而显着的损失。半纤维素和纤维素降解在整个腐烂期间稳定发生。这些结果可用于更深入地了解美国因褐腐病而退化的木框架结构的力学行为。