摘要
钢筋与混凝土之间能够协同工作的主要原因之一是两者间具有良好的粘结性能,但钢筋混凝土结构在服役过程中,侵蚀性介质会进入混凝土中引起钢筋的锈蚀,造成钢混构件粘结性能退化,进而影响混凝土结构的承载能力及服役寿命。因此,通过试验角度科学地认识钢筋锈蚀作用下钢筋混凝土之间粘结性能的变化规律,对于钢混结构的先期设计及服役期间构件的寿命预测都有着极其重要的意义。对于锈蚀钢筋与混凝土之间的粘结性能研究主要采用试验的方式,如梁式试验、中心拉拔试验及偏心拉拔试验等,通过相关的试验手段,对锈蚀钢筋混凝土构件的粘结特性(主要包括粘结强度、粘结刚度、粘结滑移量和粘结力的分布)等进行了探究,并分析了影响锈蚀钢筋混凝土构件粘结性能的因素,主要包括箍筋、混凝土特性、钢筋特性、裂缝宽度、电加速腐蚀电流密度、腐蚀形态等,并在相关试验数据的基础上建立了钢筋混凝土的粘结滑移本构关系及锈蚀率与粘结强度的关系模型。国内外仅对锈蚀作用(不考虑外荷载作用)下的钢混构件的粘结性能开展了较为系统的研究,并取得了一定的成果。研究表明,在锈蚀率较低时钢筋混凝土构件的粘结性能有所提高,但是随着锈蚀率的继续增大,粘结强度会迅速衰减。实际工程中的钢混结构,如高铁轨道梁(杂散电流与高铁荷载)、跨海大桥(环境腐蚀与车载)等,不仅受到腐蚀的威胁,还受到外载荷等其他因素的影响。但目前对腐蚀因素与外荷载(如疲劳荷载等)作用下钢混构件的粘结性能的研究相对较少。外载荷势必会对钢混构件的粘结性能造成影响,加速粘结强度的衰减,但由于影响粘结性能的因素较多、试验操作困难等,仍然需要对钢混构件的粘结性能进行深入的研究,以推动混凝土耐久性的进一步发展。本文总结了国内外研究锈蚀钢筋混凝土构件粘结性能的试验方法,从锈蚀粘结特性、粘结滑移本构关系、腐蚀疲劳作用下的粘结性能等方面综述了国内外关于锈蚀钢筋混凝土构件的最新研究成果,分析了现阶段研究中的不足之处,以期为锈蚀钢筋混凝土粘结性能的未来研究提供参考。
One of the main reasons why steel and concrete can work together is that good bond properties exist between them,but the bond propertiesof the reinforced concrete in service will degrade due to corrosion of reinforcement caused by entry of the aggressive agents,and the bearing capacity and the service life of structures will also be affected. So,it’s of great significance to understand the change rule of the bond properties from the scientific perspective,which will contribute to the pre-design and service life prediction of reinforced concrete.The experiments are mainly adopted to study the bond properties between corroded steel bar and concrete,like beam test,central pull-out test and eccentric pull-out test. Through related test methods,the bond properties are researched including bond strength,bond stiffness,bond slip and distribution of bond force. The factors affecting bond properties are analyzed like stirrups,properties of the concrete,properties of the steel,crack width,the magnitude of the applied current density and the corrosion morphology. The bond-slip constitutive laws and the relationship between the corrosion level and bond strength are established based on the statistics from the experiments. As a matter of fact,the systematic study at home and abroad has been carried out on the bond behaviour of corroded reinforced concrete members without considering external loads and good results have been achieved. The results show that the bond properties are improved when corrosion level is low,but the bond strength will rapidly decrease with the increase of the corrosion level.In the practical engineering such as high-speed rail beams( stray current and high-speed rail loads) and sea-crossing bridges( environmental corrosion and vehicle loads),the reinforced concrete structures are not only threatened by the reinforcement corrosion but affected by the external loads as well. The existence of the external loads will undoubtfully have a further impact on the bond properties and accelerate the degradation of the bond strength. In fact,the bond properties between steel and concrete under the corrosion coupled with external loads like repeated loading are comparatively less researched due to too many factors and complex test operation,which need more in-depth research to promote the further development of concrete durability.This article summarizes the experimental methods of investigating the bond behaviour and introduces bond properties,constitutive laws and bond fatigue properties of the reinforced concrete in the condition of corrosion. Finally,it points out the deficiencies of the current research results,aiming at providing some valuable ideas for the further study into the bond behaviour of the corroded reinforced concrete.
作者
孙杨
乔国富
SUN Yang;QIAO Guofu(Department of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第3期116-125,共10页
Materials Reports
基金
国家自然科学基金面上项目(51578190
51378156)~~
关键词
粘结性能
锈蚀
腐蚀疲劳
钢筋混凝土
电加速腐蚀电流
本构关系
bond properties
corrosion
corrosion fatigue
reinforced concrete
magnitude of the applied current
constitutive laws
