- 摘 要
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（1 宜春學院土木工程系， 宜春 336000； 2 南京航空航天大學土木與機場工程系， 南京 210016）
［摘要］采用電化學方法對縱筋進行銹蝕，通過加載試驗研究了再生混凝土梁在不同縱筋銹蝕率下剛度退化規(guī)律。結(jié)果表明：再生混凝土梁破壞時的極限承載力隨銹蝕率的增加而減小，當銹蝕率較小時，大約在5%極限承載力的荷載時梁在純彎段內(nèi)開始出現(xiàn)裂縫，破壞形態(tài)為適筋梁彎曲破壞；當銹蝕率較大時，破壞時裂縫分布有向跨中靠攏的趨勢。當荷載較小時，隨著縱筋銹蝕率的增加再生混凝土梁跨中撓度變化不大；當荷載較大時，跨中撓度隨縱筋銹蝕率增大而增大變得比較明顯。再生混凝土梁的剛度因縱筋銹蝕發(fā)生了一定的退化，導(dǎo)致剛度退化的主要原因是再生混凝土梁截面和縱筋橫截面面積減小以及二者之間粘結(jié)性能的退化，并基于鋼筋截面面積減小這一因素推導(dǎo)了再生混凝土梁彎曲剛度退化計算方法。
［關(guān)鍵詞］再生混凝土；鋼筋銹蝕；銹蝕率；剛度退化；彎曲剛度
中圖分類號：TU375.1文獻標識碼：A文章編號：1002-848X(2021)04-0086-05
Degradation law and calculation method of stiffness of recycled concrete beams with corroded rebars
ZOU Zhenghao1,2, YANG Guojiao1, WU Jin2, SU Tian2
(1 Department of Civil Engineering, Yichun University, Yichun 336000, China;2 Department of Civil and Airport Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)
Abstract:The electrochemical method was used to corrode the longitudinal rebars, and the stiffness degradation law of recycled concrete beams under different corrosion rate of longitudinal rebars was studied by loading tests. The results show that the ultimate bearing capacity of recycled concrete beams decreases with the increase of corrosion rate. When the corrosion rate is small, cracks begin to appear in the pure bending section at the load about 5% of the ultimate bearing capacity, and the failure mode is flexural failure of balanced-reinforced beam. When the corrosion rate is large, the distribution of cracks tends to be closer to the mid-span. When the load is small, with the increase of the corrosion rate of longitudinal rebars, the mid-span deflection of the recycled concrete beam does not change much, when the load is large, the mid-span deflection increases obviously with the increase of the corrosion rate of longitudinal rebars, and the stiffness of the recycled concrete beam is degenerated due to the corrosion of longitudinal rebars, the main reasons for the stiffness degradation are the reduction of the cross-sectional area of recycled concrete beams and longitudinal bars, and the degradation of the bond performance between them, thus the calculation method of the degradation of the flexural stiffness of the recycled concrete beam was derived based on the reduction of the cross-sectional area of the rebars.
Keywords:recycled concrete;rebar corrosion;corrosion level;stiffness degradation;flexural stiffness
*江蘇省研究生科研創(chuàng)新計劃項目（KYCX17_0272）。
作者簡介：鄒正浩，博士，講師，Email: zouzhenghao@nuaa.edu.cn；通信作者：吳瑾，博士，教授，Email:wujin@nuaa.edu.cn。
