阻燃涂料处理胶合木短柱四面受火后力学性能试验研究

Experimental research on the mechanical behavior of short glulam columns with different fire retardant coating exposed to four-side fire

通过4组14根胶合木短柱四面受火后力学性能的对比试验，研究不同截面尺寸、表面处理、受火时间后胶合木柱的剩余承载力、破坏形态和炭化速度的变化规律。研究表明，四面受火20～60min后，胶合木柱剩余承载力随受火时间增加而显著降低，下降幅度为21％～73％，且下降幅度随截面尺寸的增加而减小，截面尺寸为200×200时，下降幅度为28％～73％，截面尺寸为300×300时，下降幅度为2l％～51％。胶合木柱炭化速度随受火时间增加有所降低。提出的基于实测炭化速度剩余承载力改进计算方法的计算结果与试验结果吻合较好，可用于预测四面受火胶合木柱的剩余承载力。

The residual bearing capacity, failure mode and charring rare of 14 glulam columns in 4 series exposed to four-side fire were experimentally studied under different cross-sections, fire retardant coating and exposed time. It is found that the residual hearing capacity of exposed specimens decrease obviously while the exposed time increasing, the residual bearing capacity decreases by 21% to 73% while the exposed time increased from 20 minutes to 60 minutes. The residual bearing capacity for specimens with 200 x 200 cross-section decreased by 28% to 73% , while for 300 × 300 cross-section was 21% to 51%. The charring rate decreases with increasing exposed time. The modified calculated method for the residual bearing capacity of glulam columns based on testing charring rate agrees well with the test results, which can be used for calculating the residual bearing capacity of glulam columns.