BFRP筋-再生混凝土重复加卸载下黏结性能理论研究  

Theoretical study on the bond behavior between BFRP bar and recycle concrete under cyclic loads

作　　者：黄健 阎亮 李丽娟[2] 刘锋[2] 简嘉宇 邹睿 HUANG Jian;YAN Liang;LI Lijuan;LIU Feng;JIAN Jiayu;ZOU Rui(Huace Engineering Testing Co.,Ltd.,Guangzhou 510320,China;School of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]华测工程检测有限公司,广东广州510320 [2]广东工业大学土木与交通工程学院,广东广州510006

出　　处：《混凝土》2024年第11期100-107,共8页Concrete

基　　金：国家自然科学基金(12032009,12072080)。

摘　　要：复合材料(FRP)筋混凝土结构在土木工程中具有良好的应用前景,但是目前仍缺乏关于其疲劳性能的研究。对玄武岩纤维复合材料(BFRP)筋与再生混凝土在重复加卸载下的黏结性能进行了理论研究,并提出了黏结应力-滑移本构模型。基于静力和重复加卸载拉拔试件的试验结果,分析了BFRP筋直径、疲劳应力水平、加卸载次数对黏结性能的影响规律。BFRP筋-混凝土黏结滑移模型由重复加卸载阶段模型和此后的静力拔出阶段模型组成。在重复加卸载阶段,疲劳黏结应力-滑移曲线主要由疲劳黏结刚度和卸载点的滑移控制。研究发现,疲劳黏结刚度除与初始刚度相关外,还主要受到疲劳应力水平和疲劳次数的影响。疲劳黏结刚度的变化规律可以通过指数函数近似模拟。重复加卸载阶段的滑移主要与疲劳应力水平相关。在此基础上,提出了重复加卸载阶段的黏结应力-滑移本构模型,该模型可以考虑疲劳荷载对黏结性能的影响。在重复加卸载完成后的静力拔出阶段,研究发现历史疲劳荷载对该阶段的黏结性能无明显影响,传统的静力黏结模型仍然适用。最后,通过试验结果验证了所提出疲劳黏结应力-滑移本构模型的合理性和准确性。Fiber reinforced polymer(FRP)bar reinforced concrete structure has a promising prospect in civil engineering,but currently it is still lack of research on the cyclic behavior.This paper theoretically investigated the bond behavior between basalt FRP and recycle concrete under cyclic loads and proposed constitutive models for the stress-slip relationship.Based on the experimental results of pull-out specimens under static and cyclic loads,the effects of BFRP bar diameter,fatigue stress levels and cycling times on the bond behavior were analyzed.The constitutive model for BFRP bar-concrete cyclic bonding was consisted of the model under cyclic load and the model under static pull-out load.During the cyclic loading process,the cyclic bond stress-slip curve is mainly governed by the cyclic bond stiffness and the slip at unloading point.It was found that the initial bond stiffness,fatigue stress level and cycling times could affect the cyclic bond stiffness.The change of cyclic bond stiffness could be simulated by using an exponential function.The bond slip during cyclic loading is mainly related to the fatigue stress level.Therefore,a constitutive model was proposed for the bond stress-slip relationship of specimens under cyclic load,in which the effect of cyclic load was considered.After the complete of cyclic loading,the specimen was in the stage of static pull-out stage.It was found that the cyclic loading history did not obviously affect the bond behavior in this stage and the conventional model for static bonding is still applicable.In the end,the reasonability and accuracy of the proposed model were verified by the experimental results.

关 键 词：复合材料筋混凝土结构 本构模型 黏结理论 重复加卸载 黏结应力-滑移曲线 

分 类 号：TU528.01[建筑科学—建筑技术科学]