疲劳荷载下锈蚀钢筋混凝土粘结性能研究

Bond behavior of corroded reinforced concrete under fatigue loading

为研究复合作用对混凝土与钢筋间粘结性能的影响,设计制作了一批变形钢筋混凝土粘结试件.在疲劳和加速锈蚀同时进行后,通过粘结试件的拔出试验得到混凝土与钢筋间粘结应力滑移曲线,分析了复合作用对粘结应力滑移曲线影响,并且总结了钢筋混凝土粘结试件破坏模式.试验研究表明:在复合作用下,钢筋混凝土试件的失效模式大致可分为两类:劈裂破坏、剪切破坏.其中低循环疲劳荷载作用下的试件多出现劈裂破坏,而高循环疲劳荷载作用下的试件多为剪切破坏;在单一因素作用下,试件的粘结应力分布基本呈“单峰”分布,而在复合作用下,应力分布曲线呈“双峰”分布;复合作用后,极限粘结应力及试件破坏时滑移值都出现了一定程度的降低.

In order to study the effect of composite action on the bonding properties between concrete and reinforcement,a batch of deformed reinforced concrete specimens was designed and manufactured.After fatigue and accelerated corrosion were performed at the same time,the bond stress-slip curve about concrete and steel was obtained through the pull-out test.The effect of composite action on the bond stress-slip curve was analyzed,and the destruction mode was discussed.The research shows that under the composite action,the failure modes of reinforced concrete specimens can be roughly divided into two categories:splitting failure,and shear failure.Among the specimens under low cyclic fatigue loading,there are many cracking failures,while the test specimens under high cyclic fatigue load are mostly shear failures.Under the influence of single factor,the bond stress distribution of the specimens basically shows a“single peak”.The stress distribution curve presents a“double peak”under the combined effect.After the composite action,the ultimate bond stress and the slip value of the test piece were all reduced to some extent.