变形钢筋与混凝土黏结性能研究综述

从黏结试验方法、黏结强度和黏结应力-滑移本构关系三个方面,对单调及重复荷载作用下钢筋混凝土黏结性能相关研究进行了综述。对于中心拔出试验,钢筋与混凝土的黏结受力状态与实际工程结构有偏差,而梁式或梁端式黏结试验是相对较为理想的黏结试验方法。单调荷载作用下,对于非锈蚀钢筋混凝土,黏结强度以及黏结应力-滑移本构关系的研究均较为完善,成果已在各国或地区规范中体现;对于锈蚀钢筋混凝土,黏结强度劣化规律的研究已有大量数据积累,并已建立了以钢筋锈蚀率或锈胀裂缝宽度为变量的黏结强度劣化模型,但单调荷载作用下锈蚀钢筋混凝土黏结应力-滑移本构关系模型有待进一步完善。重复加载作用下钢筋混凝土黏结滑移性能的研究相对较少。已有研究结果表明:无论钢筋是否锈蚀,重复加载对黏结强度都没有显著影响,但是会导致钢筋和混凝土之间产生残余滑移,随加载次数和应力水平增大呈不断累积增长的趋势。根据目前研究现状,对于劈裂破坏模式下的黏结应力-滑移本构模型、腐蚀电流密度对黏结强度劣化规律的影响,基于表面锈胀裂缝宽度的黏结强度劣化模型、锈蚀钢筋与混凝土在单调及重复荷载作用下的黏结应力-滑移本构模型等,有待进一步研究。

Bond behavior between concrete and deformed steel bar: a review

In this paper, the recent research progress regarding the bond behavior of reinforced concrete (RC) under monotonic or repeated loading is reviewed from the aspects of bond test methods, bond strength and bond stress-slip relationship.The bond stress state in the concentric pullout tests cannot fully simulate the bond properties of real RC structures, while the beam tests or the beam-end tests show better performance and can realistically reflect the influence of moments and shear stresses on the bond behavior.For non-corroded RC structrues under monotonic loading, the influence of various parameters on the bond strength or the bond stress-slip law has been well recognized, and mathematical models that can provide relatively good predictions have been proposed and incorporated into national or regional codes. For corroded RC structures under monotonic loading, the deterioration of bond strength has been intensively investigated, and mathematical models with the mass loss percentage or the surface crack width as the variable have been devoloped. However, the investigations with respect to the bond-stress slip law are very limited and the current models still have room for improvement. Existing studies regarding the bond behavior of RC subjected to repeated loading are still few in number. The limited test results indicate that the bond strength is hardly affected by repeated loading, no matter whether the steel bar is corroded or not.However, repeated loading can lead to residual slip which increases with loading cycles and repeated load levels. It is concluded that further research is needed for a few issues, including the bond stress-slip law for splitting failure, the influence of corrosion current density on bond deterioration, the correlations between bond strength and surface crack width, and the bond stress-slip law of corroded steel bar under monotonic or repeated loading.