预制T形肋底板混凝土叠合板弯曲疲劳性能试验研究

为研究T形肋对混凝土叠合板弯曲疲劳性能的影响，进行了预制T形肋底板混凝土叠合板和整浇板的弯曲疲劳性能对比试验。通过对比试验得到了不同疲劳循环加载次数下的跨中挠度、混凝土应变、预应力筋应变、残余变形等，研究了试件在疲劳循环荷载下的刚度退化情况、荷载 应变分布、裂缝分布及残余承载力等。结果表明：经历200万次疲劳作用后，预制T形肋底板混凝土叠合板无明显刚度和承载力退化，增设T形肋的叠合板能达到与整浇板相同的疲劳性能。基于试验结果，给出了预制T形肋底板混凝土叠合板正截面弯曲疲劳强度计算假定以及正截面弯曲疲劳应力验算方法。

Experimental study on bending fatigue behavior of concrete composite slab with precast prestressed T-type rib panel

In order to study the influence of T-type rib on the bending fatigue behavior of concrete composite slab, the contrast experimental study was conducted between concrete composite slab with precast prestressed T-type rib panel and cast-in-place slab. During the fatigue experiments, the mid-span deflection, strain of concrete and prestressing tendons and residual deflection after different loading cycles were measured. The stiffness degradation, strain distribution, crack distribution and residual bearing capacity were analyzed. Results show that composite slabs with precast prestressed T-type rib panel have no obvious stiffness and strength degradation after two million times of fatigue cycles, which can achieve the same fatigue behavior as cast-in-place slabs. Assumptions and design formulas for normal section bending fatigue strength of concrete composite slab are put forward based on the test results.