Abstract
For strengthening of steel members suffering deterioration and/or insufficiency of load carrying capacity, externally bonding patch plate have been used. Furthermore, pretensioned patch plate have also been used in several strengthening cases. Although the pretensioned patch plate can improve stress in steel member not only by live load but also dead load, the shear and normal stress tend to be introduced in adhesive layer. The stresses may cause the reduction of debonding load of patch plate. To improve the debonding load of pretensioned patch plate, applying non-pretensioned region at the end of patch plate was proposed. In this study, prestress introduced into steel plate by partially pre-tensioned patch plate was observed. In addition, the improvement of debonding load due to the non-pretentioned region is confirmed from debonding tests. The improvement effect in the debonding load is evaluated from the view of principal stress in adhesive.
