2018 Volume 25 Issue 100 Pages 100_1-100_14
In this study, we propose two types of retrofitting methods against fatigue cracking at the upper end of vertical stiffeners under RC slab. They are steel plate reinforcement using a jack-up jig, and angle steel reinforcement using thread rolling screw (TRS). The effectiveness of those two types of retrofitting methods are experimentally investigated through fatigue tests using a large specimen with three main girders under alternative loading using two actuators. As a result, both retrofitting methods can reduce the local stress concentration at the crack initiation point to about half of that before reinforcement, and can prevent fatigue cracking.