- 摘 要
-
（上海市建筑科學(xué)研究院 上海市工程結(jié)構(gòu)安全重點實驗室， 上海 200032）
［摘要］考慮目前常用的工程竹類型膠合竹和重組竹，通過2組10根工程竹柱四面受火后力學(xué)性能的對比試驗，研究了不同受火時間后工程竹柱剩余承載力、破壞形態(tài)和炭化速度的變化。結(jié)果表明：不同受火時間后工程竹柱的剩余承載力明顯降低，受火10～20min后降低幅度達29-0%～83-1%。四面受火后工程竹柱剩余承載力下降程度隨受火時間增加而增加，隨截面尺寸增加而減小。剩余承載力下降主要是由于四面受火后工程竹柱表面炭化引起的有效截面面積減少，以及四面受火后靠近炭化層的高溫分解層強度明顯劣化所致。各組對比試件的初始剛度均明顯大于不同受火時間后試件。由于角部遭受兩個方向的熱傳遞，四面受火后工程竹柱角部炭化后變?yōu)榛⌒?，等效成矩形截面后的等效炭化速度比非角部影響區(qū)的平均炭化速度大；膠合竹柱的炭化速度比重組竹柱的炭化速度略高。
［關(guān)鍵詞］膠合竹； 重組竹； 炭化速度； 四面受火； 工程竹柱
中圖分類號：TU317-1， TU366-3文獻標識碼：A文章編號：1002-848X(2018)10-0098-05
Experimental study on mechanical behavior of engineered bamboo columns after being exposed to four-side fire
Chen Lingzhu, Leng Yubing, Xu Qingfeng, Chen Xi
(Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences, Shanghai 200032, China)
Abstract:Considering the common used engineered bamboo products of laminated bamboo and bamboo scrimber, through the comparative test on the mechanical properties of the two groups of ten engineered bamboo columns after being exposed to four-side fire, the variation of the residual bearing capacity, failure mode and charring rate of the engineered bamboo columns after being exposed to different times of fire were studied. The results show that the residual bearing capacity of the engineered bamboo column is significantly reduced after being exposed to four-side fire, and the reduction rate reaches 29%~83-1% after being exposed to 10~20 minutes fire. The degree of decline in the residual bearing capacity of engineered bamboo columns after being exposed to four-side fire increases with the increase of the fire time and decreases with the increase of the section size. The decrease in the residual bearing capacity is mainly due to the reduction of the effective cross-sectional area caused by the charring of the surface of the engineered bamboo column after being exposed to four-side fire, and the significant deterioration of the strength of the pyrolysis layer close to the char layer after being exposed to four\|side fire. The initial stiffness of the comparative specimens of each group is significantly greater than that of the specimens after being exposed to different times of fire. Because the corners are subjected to heat transfer in both directions, the corners of the engineered bamboo columns after being exposed to four-side fire become round after charring, and the equivalent charring rate after equivalent to rectangular section is greater than the average charring rate in non-corner affected areas. The charring rate of laminated bamboo columns is slightly higher than that of bamboo scrimber columns.
Keywords:laminated bamboo; bamboo scrimber; charring rate; fourside fire; engineered bamboo column
*上海市科委標準項目（17DZ2202600），上海市優(yōu)秀技術(shù)帶頭人計劃項目（15XD1522600）。
通訊作者：許清風(fēng)，博士，教授級高級工程師，Email：xuqingfeng73@163.com。
