摘要
传统木结构建筑的防火性能是制约其长期安全使用的重要因素。通过6组18根不同表面处理圆木柱受火后力学性能的对比试验研究,分析不同表面处理不同受火时间后圆木柱剩余承载力、初始刚度和炭化速度的变化规律,了解不同表面处理对圆木柱受火后力学性能的影响规律。结果表明,未受火对比试件和受火时间较短的圆木柱均呈轴压破坏特征,受火时间较长圆木柱呈偏压破坏特征。受火后试件剩余承载力较未受火对比试件降低5.3%~80.2%,降低幅度与受火时间成正比、与截面尺寸成反比;传统地仗保护试件剩余承载力损失程度明显小于表面无处理试件和表面涂抹防火涂料试件。受火后圆木柱初始刚度显著降低,降低幅度随受火时间增加而增加,有传统地仗保护试件降低幅度小于表面无处理试件。传统地仗保护试件受火炭化后表面有一层白色覆盖物,其炭化速度小于表面无处理试件。数值模拟结果与试验结果符合较好,可供传统历史木结构受火后的评估鉴定。
The fire performance of traditional timber buildings is one of the important factors restricting their long time safety.To analyze the mechanical behaviors of timbers,including residual ultimate capacity,initial stiffness and charring rate of round timber columns after different surface treatments and exposure times,6 series and a total of 18 specimens were experimentally studied.Results showed that control specimens without exposure and round columns with short exposure time exhibited axial compressive failure,while round columns with long exposure time suffered an eccentric compressive failure.The residual ultimate load-bearing capacity of exposed specimens decreased between 5.3%~80.2%,compared to that of the control specimens.The decrease of residual ultimate load-bearing capacity was proportional to fire durations,and in inverse proportion to cross-section geometry.The reduction of residual ultimate load-bearing capacity for specimens with traditional craftwork was much lower than untreated specimens and specimens treated with fire-retardant coating.The initial stiffness of round timber columns greatly decreased after fire,and the reduction increased with fire durations.The initial stiffness for specimens with traditional craftwork was much higher than untreated specimens.Specimens with traditional craftwork had a white layer on the char,and its charring rate was smaller than the untreated specimens.The simulation results were in good agreement with the test ones,which can be used for evaluation and appraisal of traditional timber buildings after fire.
作者
许清风
韩重庆
陈玲珠
王正昌
冷予冰
Xu Qingfeng;Han Chongqing;Chen Lingzhu;Wang Zhengchang;Leng Yubing(Shanghai Key Laboratory of Engineering Structure Safety,SRIBS,Shanghai 200032,China;Architects & Engineers Co.,Ltd.,Southeast University,Nanjing 210096,China;School of Civil Engineering,Southeast University,Nanjing 210096,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2019年第7期90-99,共10页
China Civil Engineering Journal
基金
国家自然科学基金青年科学基金(51808339)
上海市青年科技启明星计划项目(17QB1403400)
上海市科委标准项目(17DZ2202600)
关键词
圆木柱
传统地仗保护
防火涂料
受火后
炭化速度
round timber column
traditional craftwork
fire-retardant coating
after fire
charring rate
