研究了盐冻环境下不同配箍率试件的钢筋混凝土黏结性能劣化特性。设计了无箍筋和两类配箍试件,在同时经历15、25、30、45、50、60、70、75、80次盐冻融循环作用后,采用中心拉拔试验测试了其黏结性能,探究了盐冻融损伤和配箍率对黏结强度特征值、滑移量及黏结滑移关系的影响。结果表明:试件的黏结破坏形态主要取决于配箍率,而与盐冻融作用次数的关系不大;随着盐冻次数的增加,钢筋混凝土间的初始、开裂和极限黏结强度近似呈线性降低,黏结应力峰值滑移量呈线性增大,黏结刚度逐渐降低;经历相同盐冻融循环次数后,试件配箍率越高黏结强度、刚度及滑移量损失越小,配制箍筋可显著补强盐冻融作用导致的钢筋混凝土黏结性能退化。
It studied the effect of deicer-frosting environment on bond property degradation between steel bar and concrete of different stirrup ratio specimens by experiments.Specimens without stirrups and two classes of hooped specimens were designed.After 15,25,30, 45,50,60,70,75 and 80 fast deicer-frosting cycles, the bond behavior of three kinds of specimens were tested by axial pull-out experme- nts.The effect of deicer-frosting injury and stirrup ratio on band strength characteristic value, slippage and bond-slip relationship were explored.The test results show that the bond failure mode of specimens mainly depends on stirrup ratio and deicer-frosting cycles number has little relationship to the bond failure mode.With the increase of deicer-frosting cycles number, the original slip bond strength, cracking strength and ultimate bond strength of the specimens between steel bar and concrete decrease approximately linearly, peak slip increases linearly,bond stiffness decreases gradually.After the same number of deicer-frosting cycles,the higher stirrup ratio is,the less bond strength,bond stiffness and slippage lose, stirrups can enhance degraded bond property between steel bar and concrete greatly which caused by deicer-frosting cycles.