摘要
为研究玄武岩纤维增强再生混凝土箱梁疲劳性能,设计了10根玄武岩纤维增强再生混凝土波纹钢腹板组合箱梁,对其进行四点弯曲变幅疲劳试验。通过分析箱梁的裂纹扩展过程、破坏形态和挠度,研究再生粗骨料取代率和碳纤维复合材料(carbon fiber reinforced polymer,CFRP)加固对纤维再生混凝土箱梁疲劳性能的影响。试验结果表明:纤维再生混凝土箱梁呈现两种疲劳破坏形态,即未加固组合箱梁发生钢-混纵向滑移,CFRP加固组合箱梁在波纹钢腹板焊缝焊趾处撕裂;总体上,纤维再生混凝土箱梁表现出良好的抗变幅疲劳性能;再生粗骨料取代率是影响变幅疲劳寿命的主要因素,随着再生粗骨料取代率增加,变幅疲劳寿命分别降低了15.5%、15.5%、10.2%和31.4%;CFRP加固能有效地抑制疲劳裂纹扩展和底板与腹板的纵向滑移,增强再生混凝土抗弯刚度,进而提高组合结构的疲劳寿命;理论计算的纤维再生混凝土组合箱梁的变幅疲劳寿命均高于试验值。
To study the fatigue performance of basalt fiber-reinforced recycled concrete box girders,ten combined box girders with basalt fiber-reinforced recycled concrete corrugated steel webs were designed and subjected to four-point bending variable amplitude fatigue tests.By analyzing the crack expansion process,damage pattern,and deflection of the specimens,the effects of recycled coarse aggregate replacement rate and carbon fiber reinforced polymer(CFRP)reinforcement on the fatigue performance of the fiber-reinforced concrete box girders were investigated.The test results show that the fiber-reinforced concrete box girder exhibits two types of fatigue damage patterns,i.e.,steel-mixed longitudinal slip in the unreinforced composite box girder and tearing at the weld toe of the corrugated steel web in the CFRP-reinforced composite box girder.Overall,the fiber-reinforced concrete box girder shows good resistance to variable amplitude fatigue.The recycled coarse aggregate replacement rate is the main factor affecting the variable amplitude fatigue life,which decreases by 15.5%,15.5%,10.2%,and 31.4%,with the increase of recycled coarse aggregate substitution rate,respectively.CFRP reinforcement can effectively inhibit the fatigue crack expansion and longitudinal slip of the bottom and web slabs and enhance the flexural stiffness of the recycled concrete,which in turn improves the fatigue life of the combined structure.The theoretically calculated variable fatigue lives of fiber-reinforced concrete composite box girders are higher than the experimental values.
作者
董江峰
刘元聪
袁书成
王清远
卫志盛
DONG Jiangfeng;LIU Yuancong;YUAN Shucheng;WANG Qingyuan;WEI Zhisheng(Key Laboratory of Deep Earth Science and Engineering,Ministry of Education,Sichuan University,Chengdu 610065,China;Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province,Sichuan University,Chengdu 610015,China;College of Civil Engineering,Sichuan Agricultural University,Chengdu 611830,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2023年第S01期174-182,共9页
Journal of Building Structures
基金
成都市技术创新研发项目(2022-YF05-00501-SN)
教育部“春晖计划”合作科研项目(HZKY20220561)
关键词
波纹钢腹板组合箱梁
玄武岩纤维增强再生混凝土
CFRP加固
疲劳试验
取代率
疲劳性能
corrugated steel web composite box girder
basalt fiber reinforced recycled concrete
CFRP reinforcement
fatigue test
substitution rate
fatigue performance
