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BFRP加固对冻融损伤混凝土短柱承载能力的影响OA

Effect of BFRP strengthening on bearing capacity of freeze-thaw damaged concrete short columns

中文摘要英文摘要

为减少冻融循环对混凝土力学性能的影响,经济高效地延长严寒地区冻融损坏混凝土结构的使用寿命,通过三种BFRP布包裹层数(0,2,3层)约束经历四种冻融循环次数(0,25,50,75次)素混凝土短柱试验,系统研究BFRP布加固层数对不同冻融损伤混凝土柱承载能力影响.结果表明:在经历冻融循环后,混凝土柱极限承载力大幅降低,极限位移略有提高;3层加固使0,25,50,75次冻融循环混凝土柱的极限承载力提升20%、16%、22%、37%,还使极限位移大幅增加;由试验现象和数据分析发现,应于端部施加额外加固,以获取更好的加固效果;采用ABAQUS并选取合适材料本构模型,参照试验建立12种有限元模型,模拟结果同试验结果吻合较好;考虑FRP约束棱柱体有效约束面积划分后,代入BFRP约束混凝土柱极限应力公式和冻融损坏混凝土单轴受压应力本构关系,建立了适用BFRP约束冻融损伤混凝土短柱极限承载力公式.

This paper aimed to reduce the effect of freeze-thaw cycles on the mechanical properties of concrete and to extend the service life of freeze-thaw damaged concrete structures in severe cold regions economically and ef-ficiently.In this study,the effect of BFRP cloth reinforcement layers on the bearing capacity of concrete columns with different freeze-thaw damage was systematically investigated through three BFRP cloth wrapping layers(0,2 and 3 layers)constrained to experience four freeze-thaw cycles(0,25,50 and 75 times)for vegetated concrete short columns.The results show that after freeze-thaw cycles,the ultimate bearing capacity of concrete column is significantly reduced and the ultimate displacement is slightly increased.3 layers of reinforcement increase the ulti-mate bearing capacity of concrete column by 20%,16%,22%and 37%for 0,25,50 and 75 freeze-thaw cycles,and also increase the ultimate displacement significantly.From the analysis of the experimental phenomena and data,it was found that additional reinforcement should be applied to the column ends to obtain better reinforcement results.The simulation results of 12 finite element models were established by using ABAQUS and selecting suitable material intrinsic model with reference to the test,and the results were in good agreement with the test results.After considering the effective restrained area division of the FRP-constrained prismatic column,the ultimate stress for-mula of the BFRP-constrained concrete column and the uniaxial compressive stress principal structure relationship of the freeze-thaw damaged concrete are brought in,and the applicable BFRP-constrained freeze-thaw damaged concrete short column ultimate bearing capacity formula is established.

李志强;张宏家;孙玉洁

河北建筑工程学院土木工程学院,张家口 075000||河北省土木工程诊断、改造与抗灾重点试验室,张家口 075000||河北省高校绿色建材与建筑改造应用技术研发中心,张家口 075000河北建筑工程学院土木工程学院,张家口 075000

冻融循环BFRP加固力学性能复合材料

freeze-thaw cycleBFRP reinforcementmechanical propertycomposites

《复合材料科学与工程》 2024 (002)

89-95,101 / 8

10.19936/j.cnki.2096-8000.20240228.013

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