Çelik kirişlerin onarılmasında kullanılan CFRP levhaların ankrajlarının incelenmesi

Locally deformed beams and girders can be temporarily repaired by heat treatment but this practice causes decrease in the load capacities of the members. Besides, fiber reinforced polymer strips can be used to gain permanent retrofitting solution for the damaged members. In this study initially, the behavior of a heat treated beam with IPE-80 cross-section strengthened by Carbon Fiber Reinforced Polymer (CFRP) plates bonded with epoxy is studied. This repair technique is observed to causes a significant increase in load capacity but it is also being recognized that epoxy scatters earlier, which causes premature failure of the CFRP plate. This study suggests the implementation of anchorages through bolts or CFRP fabrics along with epoxy bonding while placing CFRP plates to retrofit the heat treated elements. Preliminary experiments conducted on plates specimen show that using anchorage by employing bolt lead to large increase compared to using anchorage made by CFRP fabric only. Then, scaled steel beams with IPE80 sections are selected and they are subjected to the three-point bending test. In the fınal stage of the study, finite element models are constructed to examine the effects of bolt anchorage on larger specimens. After verification of the finite element model, to obtain the most effective specimen a parametric study is carried out. The experimental and FEM studies determines that additional anchorage provides better bonding and causes the elements to resist larger loads. The practice medium span non-compact section with the highest web slenderness ratio has mostly increased the load capacity of its related Reference beam (35.6 %) compared to its other counterparts. Keywords: Locally damaged beams, Heat treatment, Repair, CFRP, Bolt Anchorage