Research on fatigue performance of steel-plate-concrete composite slab

摘要

Fatigue has become one of the critical issues for bridge deck with the rapid development of bridge engineering. Steel-plate-concrete composite slab has been more and more applied as bridge deck for the advantages in high bearing capacity, good fire resistance and less demand on framework. In order to study the mechanical behavior and fatigue performance of steel-plate-concrete composite slab under low-cycle fatigue loads, static test and the constant amplitude fatigue test were performed. The effects of layout of studs, arrangement of steel plate with openings, shear ratio, as well as amplitude of fatigue load on the damage development and the failure mode of steel-plate-concrete composite slab were researched and discussed. During the test, indices such as the dynamic deflection, strain of concrete and steel plate, residual deflection and residual bearing capacity were measured. The results implied that the amplitude of fatigue stress of bottom steel plate had a direct influence on the fatigue life of composite slab, while the layout of studs and the number of steel plate with openings had little effect on the fatigue performance. No slippage on the interface between concrete and bottom steel plate was discovered and the distribution of strain generally agreed with the plane-section assumption. All the specimens experienced similar development of fatigue damage and finally failed in the mode of fatigue fracture of steel plate, followed by the concrete crush in compression region. Finally, the method for prediction of the stiffness development and fatigue life of steel-plate-concrete composite slab was preliminarily established.