高温后BFRP筋与纤维混凝土黏结性能  

Bond performance between BFRP bars and fiber reinforced concrete exposed to high temperature

作　　者：李趁趁[1] 魏非凡 刘超伟 赵军[1] LI Chenchen;WEI Feifan;LIU Chaowei;ZHAO Jun(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《铁道科学与工程学报》2023年第8期3014-3025,共12页Journal of Railway Science and Engineering

基　　金：国家重点研发计划(2016YFE0125600);教育部创新团队发展计划(IRT_16R67)。

摘　　要：为了提高高温后玄武岩纤维复合材料(BFRP)筋与混凝土的黏结性能,分别在混凝土中单独掺入玄武岩纤维及混合掺入玄武岩纤维与纤维素纤维,通过BFRP筋与混凝土中心拔出试验对BFRP筋与纤维混凝土黏结性能开展系统研究。试验参数包括温度、基体混凝土类型、BFRP筋表面形式、黏结长度与BFRP筋直径,试验获得了BFRP筋与混凝土试件的破坏形态、黏结滑移曲线、黏结强度。研究结果表明:随着温度的升高,BFRP筋与普通混凝土、单掺玄武岩纤维混凝土及混掺玄武岩和纤维素纤维混凝土的黏结强度均逐渐降低,在70~350℃之间,它们相应的黏结强度降低率分别为17.1%~48.6%,14.5%~46.8%和11.4%~48.3%。与普通混凝土相比,单独掺入0.20%体积掺量玄武岩纤维使得深肋筋、喷砂筋、浅肋筋与混凝土的黏结强度分别提升8.4%~18.8%,56.3%~99.6%和27.5%~51.8%。混掺0.15%玄武岩纤维和0.10%纤维素纤维使得深肋筋与混凝土的黏结强度提升了17.6%~35.1%。不同BFRP筋表面形式对BFRP筋与纤维混凝土黏结强度影响显著,其中深肋筋与纤维混凝土黏结强度最高。随着黏结长度和直径的增加,BFRP深肋筋与纤维混凝土黏结强度均逐渐降低。最后,考虑上述各因素,引入BFRP筋外形系数、纤维增强系数、黏结强度折减系数,提出了高温后BFRP筋与纤维混凝土黏结强度计算公式。研究成果可为FRP筋纤维混凝土结构抗火设计和火灾之后结构的安全评估提供数据和理论支持。In order to improve the bonding performance of basalt fiber reinforced polymer(BFRP)bars and concrete after high temperature,basalt fibers were added into concrete separately,and basalt fibers and cellulose fibers were mixed into concrete.The bonding performance of BFRP bars and fiber reinforced concrete was systematically studied by the center pull-out test of BFRP bars and concrete.The test parameters included temperature,matrix concrete type,BFRP bar surface form,bonding length,and BFRP bar diameter.The failure modes,bond stress-slip curves,bond strength of BFRP bars and concrete specimens were obtained.The results show that with the increase of temperature,the bond strength between BFRP bars and ordinary concrete,basalt fiber reinforced concrete and hybrid fiber reinforced concrete decreased gradually,between 70℃and 350℃,the corresponding reduction rates of bond strength are 17.1%~48.6%,14.5%~46.8%and 11.4%~48.3%,respectively.Compared with ordinary concrete,the bond strength of BFRP bars with deep ribs,sand coating,and shallow ribs and concrete is increased by 8.4%~18.8%,56.3%~99.6%and 27.5%~51.8%by adding 0.20%basalt fiber into concrete,respectively.Mixing 0.15%basalt fiber and 0.10%cellulose fiber into concrete results in the increases by 17.6%~35.1%of the bond strength between BFRP bars with deep ribs and concrete.Different surface forms of BFRP bars have a significant effect on the bond strength between BFRP bars and fiber reinforced concrete,and the bond strength between deep rib bars and fiber reinforced concrete is the highest.With the increase of bond length and diameter,the bond strength between BFRP bars with deep ribs and fiber reinforced concrete decrease gradually.Finally,considering the above factors,the calculation formula of bond strength between BFRP bars and fiber reinforced concrete after high temperature was proposed by introducing the shape factor of BFRP bars,fiber reinforcement factor and bond strength reduction factor.The research results can provide data and theoretical support fo

关 键 词：高温 BFRP筋 玄武岩纤维 纤维素纤维 黏结性能 

分 类 号：TU528.572[建筑科学—建筑技术科学]