摘要
通过6根未受火和12根明火试验后的方钢管钢筋混凝土轴压短柱静力试验,研究了升温时间和配筋率对受火后方钢管钢筋混凝土短柱剩余承载力、刚度和延性的影响;对于升温时间30 min和60 min轴压短柱,分别测量了升温过程中关键位置的温度分布情况。试验结果表明:与常温轴压短柱相比,升温30 min且配筋率分别为1.45%及3.26%的轴压短柱,其剩余承载力、轴压刚度和延性分别降低13.4%及5.4%、20.8%及24.3%和31.9%及44.0%;对于升温60 min轴压短柱,其剩余承载力、轴压刚度和延性分别降低23.3%及12.8%、37.5%及39.1%和52.5%及61.5%。在试验基础上,结合GB50936—2014《钢管混凝土结构技术规范》给出了火灾后方钢管钢筋混凝土轴压短柱剩余承载力计算式,其计算结果与试验结果吻合较好。
In order to research the effects of exposure time and reinforcement ratio on the residual load bearing capacity, stiffness and ductility of reinforced concrete-filled square hollow section （RCFSHS） columns, six specimens at ambient temperature and twelve specimens after exposure to fire were tested. For the tests with 30 minutes and 60 minutes exposure time, temperature distribution in typical sections of columns were measured at their heating stages. The test results show that when compared to the non-exposed tests, after 30 min exposure, for those columns with reinforcement ratios of 1.45% and 3.26%, their residual load bearing capacity, axial compressive stiffness and ductility are respectively reduced by 13.4% and 5.4%, 20. 8% and 24. 3% , 31.9% and 44.0%. Correspondingly, after 60 min exposure, the residual load bearing capacity, axial compressive stiffness and ductility are reduced by 23.3% and 12. 8% , 37.5% and 39. 1% , 52. 5% and 61.5% , respectively. Based on the experimental statistics and Code GB 50936--2014, a design formula was proposed for predicting the residual axial load bearing capacity of RCFSHS columns after exposure to fire. It is shown that the calculated results predicted by the proposed formula agree well with the experiment results.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2017年第4期81-89,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51208246
51278153)
关键词
方钢管钢筋混凝土柱
高温试验
轴压试验
静力性能
reinforced concrete-filled square hollow section column
high temperature test
axial compression experiment
static behavior
