The failure mode, yielding load, debonding load and peak load were recorded and compared, and the related mechanism was discussed.
Cracking load, yielding load, ultimate load, mid-span deflection, longitudinal reinforcement strain and crack pattern of the reinforced SCC beams were investigated.
To evaluate yielding loads of continuous bridges, an uncracked section method considering moment redistribution which is defined in EUROCODE 4, was considered.
Full scale beams achieved 18 54% increase in peak load and 9 46% increase in yielding load, depending on number of FRP layers and type of fibers and resin.
It was also found that the yielding load of the strengthened beams increased significantly with areas strengthened by CFRP sheets and steel bars, while the maximum allowable long-term load only increased slightly.
The work clearly demonstrates that under certain conditions the load response of the sandwich beam can become nonlinear and unstable, and hence will fail well below face sheet yielding load because of the loss of stiffness of the core material.
The amount of yielded tissue was most sensitive to the orientation of the applied apparent loading, with the most tissue yielding for loading along the principal trabecular orientation and the least for loading perpendicular to it, regardless of the assumed tissue level yield criterion.
The theoretical yield loads were lower compared with the observed experimental yielding loads.
These STMs define the yielding load of the reinforcement, but further load increase after yielding is limited by the punching failure of each pile cap.
A parametric study concluded that higher prestressing levels improved the cracking and yielding loads, but decreased the beam ductility compared with beams strengthened with nonprestressed NSM FRP bars/strips.
