Abstract
Fatigue prediction life of RC slabs is carried out using S-N curve equation and punching shear capacity equation. However, the punching shear capacity has a significant effect on the number of repetitions to failure estimated from S-N curve equations. In particular, in the design criteria amended in 1980, the slab thickness was increased considerably in accordance with the design span of RC slabs, the design volume of vehicular traffic, and the difficulty of construction. As a result the punching shear capacity was increased, so the number of repetitions to failure estimated from the S-N curve also increased, and the number of years'service also increased greatly, which was not a practical result. Therefore in this research the punching shear capacity with respect to slab thickness was smoothed, taking into consideration the slab spans prescribed in the Specifications For Highway Bridges, to enable life prediction and integrity evaluation to be carried out for slab span lengths up to 4.0 m as prescribed by the specifications for highway bridges.
