海洋大气环境下钢筋混凝土梁的时变性能

箍筋位于纵筋外侧,往往更早发生锈蚀而且锈蚀更加严重,使梁的剪切性能比弯曲性能退化更快,梁的破坏模式可能由未锈时的弯曲破坏转为锈蚀后的剪切破坏。通过对海洋大气环境下钢筋混凝土梁的时变性能进行分析,研究了锈蚀梁承载力退化和破坏模式转换,并分析起锈时间、箍筋直径和混凝土强度等因素的影响。分析结果表明:随着服役时间的增加,梁中箍筋会先于纵筋发生锈蚀,从而使梁的破坏模式从弯曲破坏向剪切破坏转换;延长钢筋起锈时间、增大箍筋直径、提高混凝土强度均能延缓梁的受力性能退化,并延缓锈蚀梁破坏模式转换的时间。

Time-dependent behavior of RC beams under marine atmospheric environment

Corrosion of stirrups is always more severe than that of longitudinal steel bars, leading to possible shear failure instead of bending failure. This paper presents a study conducted by the authors on the effects of stirrup corrosion on the shear behavior of reinforced concrete beams. On this basis, the time-dependent behavior of RC beams in marine atmosphere was analyzed, and the degradation of bearing capacity and failure modes of the corroded beams were discussed. The influences of corrosion initiation time, stirrup diameter and concrete strength were also analyzed. The results show that with the increase of service time, the stirrups in the beam corrode before the longitudinal steel bars, which causes shear failure instead of bending failure. The degradation of structural behavior and the change of failure mode can be delayed by extending the corrosion initiation time, increasing the stirrup diameter and the concrete strength.