锈蚀对钢筋与轻骨料混凝土黏结性能的影响

EFFECT OF CORROSION ON BONDING BEHAVIOR BETWEEN REBAR AND LIGHTWEIGHT AGGREGATE CONCRETE

为了研究箍筋、钢筋锈蚀等对轻骨料混凝土与钢筋之间黏结性能的影响,制作了18个钢筋轻骨料混凝土试件,分有箍筋、无箍筋两类试件,每类试件又分无锈蚀（锈蚀率为0%）、轻度锈蚀（锈蚀率为1%）、中度锈蚀（锈蚀率为3%）、重度锈蚀（锈蚀率为5%）四种工况,采用电化学法加速钢筋的锈蚀,通过拉拔试验,得到各个试件的荷载-滑移曲线,通过黏结力-滑移曲线、每种工况试件的特征值,分析了箍筋、钢筋锈蚀程度对锈蚀钢筋与轻骨料混凝土黏结性能的影响。结果发现：箍筋对锈蚀钢筋与轻骨料混凝土的黏结性能影响很大,箍筋的存在可以提高试件的黏结强度,延缓试件在极限荷载时劈裂破坏,甚至变成延性破坏。随着锈蚀程度的增加,轻骨料混凝土与钢筋的黏结性能有先增加后减小的趋势。

In order to study the effects of stirrups and reinforcement corrosion on the bonding behavior between rebar and lightweight aggregate concrete,18 reinforced lightweight aggregate concrete specimens were made with or without stirrup,and these specimens could be divided into no corrosion（corrosion ratio was 0%）,mild corrosion（corrosion ratio was 1%）,moderate the corrosion（corrosion ratio was 3%） and severe corrosion（corrosion ratio was 5%） in four conditions. Accelerating the corrosion ratio of steel by using electrochemical method,through the pull-out tests,the load-slip curve of each specimen was obtained,and combined with the characteristic value of specimen in each condition to analyze the influence of stirrups and reinforcement corrosion on the bonding behavior between corroded rebar and lightweight aggregate concrete. The results showed that the stirrup had a great influence on the bond strength between the corroded rebar and the lightweight aggregate concrete. The existence of the stirrup could improve the bond strength of the specimen,and delay the splitting failure of the specimen under the ultimate load and even become ductile failure. With the increase of the corrosion degree,the bonding behavior between the lightweight aggregate concrete and rebar increased at first and then decreased.