The stair floor deck of the standard design pedestrian overpass is prone to corrosion due to stagnant water. In addition, the progression from corrosion to defect is faster than that of road bridge due to the thinner plates. In other words, an expected initial performance will degrade significantly by the progression of corrosion. In this study, a loading experiment was conducted using full size test body to evaluate the effect of corrosion loss on performances. As a result, the responses of the floor deck were quantitatively demonstrated using load-displacement relationships and strain states in relate to the position of corrosion loss and loading. Furthermore, the deflection limits are not met in some loading cases due to changing the boundary conditions by corrosion loss.
