Abstract
According to the increasing of 2- or 3-plate girder systems and open-box girder ones in short- and medium-span highway bridges, the span lengths of concrete slabs have become longer than the one of ordinary multi-girder systems. As one of the method dealing with this problem, 2-way slabs supported by main girders and cross beams seem to be effective because of not only reducing the bending moment caused by wheel load, but also improving the durability by relaxing shear concentration by arranging main reinforcements parallel with moving wheel. Therefore, in order to certify the deterioration mechanism of the 2-way slabs, fatigue tests by using wheel-running machine were carried out Then, a FEM analysis modeling the cracks by gap elements with rotational and shear spring, was developed and the test results were evaluated with the relation between the influence of strength and repeating number of wheel load on the decreasing stiffness of the slab and the deterioration rate.
