FRP筋与混凝土粘结滑移试验研究

目的 探讨FRP筋混凝土试件的受力过程和破坏形式,建立FRP筋与混凝土粘结-滑移本构关系模型.方法 对84个FRP筋混凝土试件进行单端拉拔试验,分析试验结果 ,对试件荷载(粘结应力)-滑移关系曲线进行研究.结果 试验结果 表明,试件的受力过程划分为两种形式,即肋未剥离劈裂破坏和肋剥离断裂破坏.肋未剥离劈裂破坏的受力过程分为微滑移、滑移、劈裂、下降和残余阶段;肋剥离断裂破坏的受力过程分为微滑移、滑移、剥离断裂和下降阶段.结论 FRP筋混凝土试件的受力过程和破坏形式与FRP筋表面肋有重要关系;基于肋未剥离劈裂破坏的试验结果 建立的FRP筋与混凝土粘结-滑移本构关系模型能够比较真实地反映试件粘结滑移全过程实际受力特征.

Experimental Study on Bond-Slip Behavior between FRP Bars and Concrete

In all,84 tensile tests of concrete specimens reinforced with FRP bars and the results obtained are studied in this paper.The process of bearing capacity and failure form of specimens are discussed in detail.The load(average bond stress)-slip relationship of FRP bars to concrete under direct pullout is analyzed.The experimental results show that the process of bearing capacity of concrete specimens reinforced with FRP bars has connection with the rib of FRP bars.The two forms of the non-exfoliation splitting failure and the exfoliation failure of the rib are divided.The process of bearing capacity of the former includes minute slip,slip,splitting,descending and residual stage and that of the latter includes minute slip,slip,collapsing,descending stage.In addition,a new model is proposed for the entire curve of the bond-slip constitutive law.It can be seen that the proposed bond-slip gives results in close agreement with the experimental results.