粘貼鋁合金板加固鋼筋混凝土梁的界面剪應力

楊立軍 鄧志恒 梁朋 楊海峰

摘要：為給粘貼鋁合金板加固鋼筋混凝土（Reinforce Concrete，RC）梁的鋁合金板和RC梁的連接設計提供依據，對其粘貼界面剪應力開展了理論和試驗研究。假設結構膠剪切變形沿厚度方向線性變化，根據粘貼界面位移協調條件，得到了一般荷載作用下的無附加錨固鋁合金板加固RC梁的粘貼界面剪應力的通解。在此基礎上，給出了常見荷載作用下的粘貼界面剪應力解析表達式和最大值。考慮鋁合金板厚度和U形箍連接等影響因素，設計了6根鋁合金板加固RC梁，對其進行了簡支梁三分點加載試驗。考慮鋁合金板正應力和界面剪應力的關系式，通過密布在鋁合金板縱軸線上的應變片測得了鋁合金板的粘貼界面剪應力。根據理論計算和試驗結果，得到了界面剪應力分布曲線和最大剪應力。研究結果表明：界面剪應力的理論和試驗結果符合較好，呈現相同的變化規律：界面剪應力在板端取得最大值后迅速滑落至橫軸附近，裂縫截面界面剪應力呈現波動。隨著鋁合金板厚度和板端與支座距離變大，板端界面剪應力也越大，結構膠厚度越大，最大界面剪應力越小，設置U形箍連接，界面剪應力變小。

關鍵詞：鋁合金板;加固;鋼筋混凝土梁;界面剪應力;粘貼界面

中圖分類號：TU398 文獻標志碼：A 文章編號：20966717（2020）04011311

收稿日期：20191201

基金項目：國家自然科學基金（51478126、51768004）

作者簡介：楊立軍（1976 ），男，教授，博士，主要從事建筑結構加固理論研究，Email： yanglj9601@163.com。

鄧志恒（通信作者），男，教授，博士生導師，Email： dengzh@gxu.edu.cn。

Received：20191201

Foundation items：National Natural Science Foundation of China （No. 51478126， 51768004）

Author brief：Yang Lijun （1976 ）， professor， PhD， main research interests： reinforcement theory of building structure， Email： yanglj9601@163.com.

Deng Zhiheng （corresponding author）， professor， doctorial supervisor， Email： dengzh@gxu.edu.cn.

Interfacial shear stress of reinforce concrete beam strengthened with aluminum alloy plate

Yang Lijun1， 2， 3， 4， Deng Zhiheng3， Liang Peng4， Yang Haifeng3

（1.Hunan Province Cooperative Innovation Center for the Construction & Development of Dongting Lake Ecological Economic Zone， Changde 415000， Hunan， P.R. China; 2.College of Civil and Architecture Engineering， Hunan University of Arts and Science， Changde 415000， Hunan， P.R. China; 3.College of Civil Engineering and Architecture， Guangxi University， Nanning 530004， P.R. China; 4.Decheng Construction Group Co. Ltd.， Changde 415000， Hunan， P.R. China）

Abstract： The theoretical and experimental researches on the bond interfacial shear stress of the RC beams strengthened with aluminum alloy plate （AAP） were carried out， in order to provide basis for the connection design between AAP and RC beam. It is assumed that the shear deformation of structural adhesive changes linearly along the thickness direction. Then the general solutions of the interfacial shear stress of the RC beam strengthened with AAP without anchorage under general loads were obtained according to the displacement coordination condition of the bonding interface. The analytical expression and maximum value of the interfacial shear stress under several common loads were given. Considering the influencing factors such as the thickness of AAP and Uwraps connection， 6 RC beams strengthened with AAP were designed， and the threepoint loading tests of simply supported beams were carried out. Based on the relationship between the normal stress and the interfacial shear stress of the AAP， the interfacial shear stresses of the AAP were got by the strain gauge densely attached to the longitudinal axis of the AAP. According to the theoretical and experimental results， the interfacial shear stress distribution curves and the maximum interfacial shear stress were obtained. The results show that the theoretical and experimental results of the interfacial shear stress distribution curves are in good agreement， showing the same change law： the interfacial shear stress quickly falls to the vicinity of the horizontal axis after reaching the maximum at the plate end. After the crack appears， the curve fluctuates at the crack. As the thickness of AAP and the distance between plate end and support become larger， the interfacial shear stress becomes also greater， the thickness of structural adhesive becomes larger， the interfacial shear stress becomes smaller， and setting Uwraps connection， the interfacial shear stress becomes smaller.

Keywords：aluminum alloy plate; strengthening; reinforced concrete beam; interfacial shear stress; bonding surface