预应力FRP加固RC梁受弯剥离承载力分析

摘　要: 受弯剥离破坏是预应力纤维加固复合材料（FRP）片材加固受弯钢筋混凝土（RC）构件的主要破坏模式。本文以预应力FRP片材加固RC梁为研究对象，理论推导结合试验验证，分析该类构件由中部弯曲裂缝引起界面剥离的承载力。基于FRP-混凝土界面粘结滑移的双线性模型，推导弯曲裂缝间界面的粘结剪应力，提出了预应力FRP片材加固RC梁由弯曲裂缝引起界面开始剥离以及发生剥离破坏的预测模型。试验结果表明：FRP的预应力越大，加固梁的剥离承载力越高；无论是预应力还是非预应力FRP加固梁，利用本文的剥离预测模型均可得到较好的结果。

Analysis for Debonding Strengthened of RC Beams Strengthened with Prestressed FPR Laminates

Abstract: Intermediate crack debonding of reinforced concrete (RC) beams flexually strengthened with prestressed fiber reinforced polymer (FRP) is a usual failure mode. The main objective of this paper is to study the debonding strength of the strengthened beams based on theoretical derivation and experimental validation. Firstly the distribution of the interfacial shear stress of the intermediate crack zone is presented based on the bilinear bond-slip model for the interface between FRP and concrete, Then, theoretical models to predict the load at initiation of debonding and deboning failure are proposed, respectively. Finally, experimental results validate the prediction models. The results showed that the debonding load increase with the prestress level. Through comparisons with other available models, the proposed model is shown to provide accurate prediction of deboning failure load of the prestressed and non-prestressed strengthened beams.