部分剪力连接的橡胶集料混凝土-钢组合梁疲劳性能试验研究

为研究橡胶集料混凝土-钢组合梁的疲劳性能,对6个试件进行疲劳试验.试验考虑了橡胶集料混凝土、剪力连接程度、栓钉直径及截面尺寸对组合梁疲劳寿命、损伤累积及破坏模式的影响.试验测试并分析了组合梁在不同荷载循环次数下的混凝土应变、残余滑移、残余挠度、滑移刚度及弯曲刚度.试验结果表明:部分剪力连接的组合梁在疲劳过程中不符合平截面假定;组合梁的疲劳破坏模式为剪跨区栓钉剪断,破坏具有较大的延性;橡胶集料混凝土能有效减小裂缝宽度,明显提高疲劳寿命,并增大残余滑移,表现出更好的延性;增大剪力连接程度可提高组合梁的疲劳寿命,并降低刚度退化作用;较大的栓钉直径使组合梁疲劳性能降低,并表现出较大的塑性.研究成果可为橡胶集料混凝土在组合梁中的应用提供依据.

Experiment Study on the Fatigue Behavior of Partial Shear Connected Composite Beam with Crumb Rubber Concrete

In order to study the fatigue behavior of the crumb rubber concrete and steel composite beam, six fatigue tests were conducted. This study focused on examining the influence of the rubber particles, shear connection degree, stud diameter and sectional dimension on the fatigue life, accumulated fatigue damage and failure mode. Concrete strain, residual slip, residual deflection and bending stiffness of the composite beams at different loading cycles were measured and analyzed. The test results showed that the plain section assumption cannot be applied to the partial connected composite beams under fatigue loading; the fatigue failure was governed by the shank failure of the studs showing good ductility in the shear span; crumb rubber concrete decreased the crack width and improved the fatigue life effectively; larger residual slip due to the rubber particles improved ductility; larger shear connection degree increased the fatigue life and reduced the shear stiffness degradation; and larger diameter of the studs decreased the fatigue life and ductility. It is shown that this study is helpful for the application of crumb rubber concrete into the composite beams.