CFRP布加固负弯矩区的钢-混凝土组合梁抗火性能研究  

Study on Fire Resistance of Steel-concrete Composite Beams Reinforced by CFRP Sheets in Negative Moment Zone

作　　者：周焕廷[1] 米康佳 陈志华[1] ZHOU Huan-ting;MI Kang-jia;CHEN Zhi-hua(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,武汉430070

出　　处：《武汉理工大学学报》2024年第3期40-47,共8页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(52378533)。

摘　　要：为研究碳纤维增强复合材料(Carbon Fiber Reinforced Polymer,CFRP)加固负弯矩区混凝土对组合梁抗火性能的影响,建立了CFRP布加固组合梁在火灾下的数值模型。通过分析组合梁的跨中挠度、负弯矩区混凝土应力、截面弯矩随温度变化的规律,研究了CFRP布黏结宽度、黏结长度对组合梁抗火性能的影响。结果表明:粘贴CFRP布能够延缓混凝土受拉应力的发展;CFRP布的端部及纵向边缘处会产生较高的界面应力,达到极限黏结应力时发生脱粘破坏;增加CFRP布黏结宽度,可提高组合梁高温下的承载能力,防止CFRP布发生脱粘破坏,建议黏结最佳宽度为200 mm;黏结长度小于1600 mm,耐火性能随黏结长度的增大而增大,大于1600 mm时,对耐火性能贡献不大。In order to study the effect of carbon fiber reinforced polymer(CFRP)reinforced concrete in the negative moment zone on the fire resistance of composite beams,a numerical model of CFRP sheets reinforced composite beams under fire was established.By analysing the mid-span deflection of the combined beam,the stresses of the concrete in the negative moment zone and the cross-section bending moment with the temperature,the effects of the bond width,length and load ratio of the CFRP sheets on the fire resistance of the combined beam were investigated.The results show that,the bonding of CFRP sheets effectively slows down the development of tensile stress in concrete,the end of the CFRP sheets and the longitudinal edges produce high interfacial stress,and debonding occurs when it reaches the ultimate bond stress.The increase of the bonding width of the CFRP sheets improves the load carrying capacity of the composite girder,and prevents debonding from occurring.The optimum width of bonding is 2oo mm.The bonding length is less than 16oo mm,the fire resistance performance increases with the increase of bonding length,and when it is greater than 16oo mm,it does not contribute much to the fire resistance performance.

关 键 词：钢-混凝土组合梁 CFRP布加固 负弯矩区 抗火 

分 类 号：TU398[建筑科学—结构工程]