摘要
通过对8根足尺钢筋混凝土梁进行恒载-升温条件下的火灾试验,分析不同边界条件、剪跨比及箍筋间距对梁高温下抗剪性能的影响,研究梁受火过程中截面混凝土的温度场、箍筋及纵筋的温度变化,梁的竖向位移、梁端水平位移及梁的最终裂缝开展形式,对比了不同参数影响下各梁的耐火极限。结果表明:剪跨比对钢筋混凝土梁高温下的抗剪性能影响显著,剪跨比越小,梁发生剪切破坏时的耐火极限越高,但破坏时的脆性特征更加明显;火灾下,随着箍筋间距的增加,梁的耐火极限降低;与常温下不同,高温下约束梁由于发生了内力重分布,其抗剪性能优于简支梁。
Eight full-scale reinforced concrete(RC)beams were tested for fire resistance.The effect of boundary conditions,shear span to effective depth ratios,stirrup spacings on shear properties of beams at high temperature was analyzed.The thermal fields within beams,variations of temperature of reinforcing bars,vertical and horizontal displacement and crack developing modes of beams were studied.The fire resistance of RC beams with different parameters was compared.The results showed that the shear span to effective depth ratios had significant influence on shear properties of beams at high temperature,with shear span to effective depth ratios decreased,the fire resistance of beams was improved,however,the failure characteristics of beams were obviously brittle.With stirrup spacings of beams increased,fire resistance of beams was decreased in fire.Different from at room temperature,fire resistance of simply supported beams was better than that of restrained beams,due to internal force redistribution of beams at high temperature.
作者
杨志年
齐建全
段开达
严建基
孙兴威
王兴国
YANG Zhinian;Qi Jianquan;DUAN Kaida;YAN Jianji;SUN Xingwei;WANG Xingguo(College of Civil and Architectural Engineering,North China University of Science and Technology,Tangshan 063210,China;Earthquake Engineering Research Center of Hebei Province,Tangshan 063210,China)
出处
《工业建筑》
CSCD
北大核心
2020年第10期57-62,共6页
Industrial Construction
基金
国家自然科学基金项目(51608196)
河北省高等学校青年拔尖人才计划项目(BJ2018008)
河北省高等学校科学技术研究项目(ZD2020139)。
关键词
钢筋混凝土梁
高温下
箍筋间距
剪跨比
抗剪性能
RC beam
under high temperature
stirrup spacing
shear span to effective depth ratio
shear property
