Design method of end anchored FRP strengthened concrete structures

摘要

This study presents a new design method of end anchored (EA) fiber reinforced polymers (FRP) strengthened concrete structures. A previously developed analytical model is modified to predict the performance of EA-strengthened concrete structures under direct pullout loading. The typical performance is composed of five stages, where excessive deformation occurs in the end anchorage during the last two stages. The ultimate loads under different failure modes are obtained, showing that low axial stiffness of the end anchorage results in low increase in the ultimate load and premature debonding failure (before ductility is developed in the end anchorage), whereas high axial stiffness significantly increases the ultimate load and yields brittle failure such as FRP rupture. Effects on the bond performance due to various axial stiffness and strength of the end anchorage are investigated in a sensitivity study. To achieve good ultimate load and ductility, critical strength and axial stiffness of end anchorage is derived. Finally, a design method is proposed for the EA-strengthened concrete structures.