碳纤维布约束对锈蚀钢筋与混凝土间粘结性能的影响  

Confining effects of carbon fiber composite sheets on bond behavior between corroded steel bars and concrete

作　　者：张伟平[1] 崔玮[1] 顾祥林[1] 王晓刚 

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《建筑结构学报》2009年第5期162-168,共7页Journal of Building Structures

基　　金：国家自然科学基金项目(50508028);国家重点基础研究发展计划(973计划)项目(2009CB623200)

摘　　要：通过外加电流加速锈蚀法获取锈蚀钢筋混凝土试件,采用横向粘贴碳纤维布的方法进行加固,设计并制作了未加固锈蚀试件、先锈蚀后加固和先加固后锈蚀三组22个试件。考虑保护层厚度、加固前或加固后的钢筋锈蚀率等因素,通过拉拔试验研究了碳纤维布约束对锈蚀钢筋与混凝土间粘结性能的影响。分析结果表明,碳纤维布的约束作用能显著提高锈蚀后钢筋与混凝土间的粘结性能,试件破坏模式由混凝土劈裂破坏向钢筋拔出破坏转变。未加固锈蚀试件极限粘结强度随着锈蚀的发展而降低;锈蚀试件采用碳纤维布加固后,由于保护层的劈裂受到约束,极限粘结强度显著提高;由于碳纤维布对锈胀力和保护层劈裂的双重约束作用,先加固后锈蚀试件的极限粘结强度随着锈蚀的发展而增大,且比同等锈蚀率的先锈蚀后加固试件更为显著。根据试验结果分别建立了不同约束条件下锈蚀钢筋与混凝土间极限粘结强度的计算模型。Twenty-two specimens with different cover depths, corrosion degrees with or without strengthening using transverse carbon fiber composite sheets were tested. Reinforcement corrosion in specimens was generated by the impressed current method. Pull-out tests were carried out to study the effects of carbon fiber composite sheets wrapping on bond behavior between corroded steel bars and concrete. It is found from the test that the bond behavior between corroded steel bars and concrete can be improved significantly by the confinement provided by carbon fiber sheets, and the failure mode tends to change from concrete splitting to pulling out of steel bars after strengthening. The ultimate bond strength of unstrengthened and corroded specimens decrease with the development of reinforcement corrosion, but it can be improved obviously by composite sheets glued transversely on the surface of the specimen. Due to the confinement of carbon fiber composite sheets to both volume expansion of corrosion products and concrete splitting, the specimens which are corroded by the impressed current method after strengthening shows higher ultimate bond strength than specimens which are strengthened after corroded, as the degree of corrosion increased. Based on test results, calculation models are proposed for the calculation of the bond strength between corroded steel bars and reinforcement under different confinement conditions.

关 键 词：钢筋混凝土 锈蚀 碳纤维布加固 拉拔试验 粘结性能 

分 类 号：TU375[建筑科学—结构工程] TU317.1