摘要
竹集成材是一种将竹材加工成竹片并进行干燥、胶合而成的层集材.本文共进行了3组侧压竹集成材的长期受弯性能试验研究,长期试验开始前通过试验确定梁的受弯极限承载力,以此作为确定长期荷载施加值的依据.长期试验的持续时间为8个月,在此期间,得到了侧压竹集成材梁不同应力条件下的蠕变变形实测数据.研究表明:在不同应力水平下,构件的蠕变变形曲线与典型的蠕变变形曲线较为接近;应力水平对侧压竹集成材梁蠕变变形有着重要的影响,应力水平低,蠕变变形程度相对较小,当加载水平高于正常使用荷载时,其蠕变变形的发展更为明显;在实际工程设计中,应考虑侧压竹集成材梁在高应力水平的长期荷载作用下蠕变破坏的可能;侧压竹集成材梁的正常使用荷载标准值取极限承载力的45%更为经济.
Laminated bamboo is a kind of laminated veneer lumber fabricated by bamboo strip after drying and gluing. Three groups of side-pressure laminated bamboo beams are prepared and tested to study the flexural performance under long-term load, and experiments are carried out to test the ultimate flexural capacity and consequently determine the value of the long-term load prior to the actual experiment. The observation time of the long-term test is 8 months, during the observation time the experimental data including creep deformation under different stress conditions are acquired. The test results show that the creep deformation curves of the beams are relatively close to the typical creep deformation curves under different stress levels. Moreover, the stress level has an important influence on the creep deformation of the side-pressure laminated bamboo beams, the creep deformation degree is relatively small when the stress level is low, and the obvious deformation can be observed while the load level exceeds the working load. In the actual engineering design, it is necessary to consider the failure of the side-pressure laminated bamboo beams under long-term load of high stress. Additionally, it is more economical to take 45% of the ultimate bearing capacity as the standard value of working load of the side-pressure laminated bamboo beams.
作者
袁平
雷婧
陈伯望
YUAN Ping;LEI Jing;CHEN Bowang(College of Civil Engineering,Central South University of Forestry and Technology,Changsha,Hunan 410004,China)
出处
《湖南城市学院学报(自然科学版)》
CAS
2020年第4期6-10,共5页
Journal of Hunan City University:Natural Science
基金
长沙市科技计划项目(kq1901135)。
关键词
侧压竹集成材梁
长期受弯试验
长期荷载取值
蠕变性能
side-pressure laminated bamboo beam
bending test under long-term load
the value of long term-load
creep property