Experimental investigations were conducted to evaluate the effects of multiple cycles of damage followed by heat straightening repair on the structural properties and fracture toughness of steel bridge beams. Six W24×76 (or equivalent) beam specimens made from A7, A588, or A36 steel (two beam specimens of each steel type) were subjected to three cycles of damage followed by heat straightening repair. In each cycle, the beam specimens were damaged statically in weak axis bending and were repaired with several half-depth vee heats and an external restraining force. Material specimens were machined from the flanges of the damaged-repaired beam specimens and tested according to ASTM standards. The material test results indicated that multiple damage-repair cycles did not have a significant influence on the elastic modulus, ultimate stress, and surface hardness of the steels. Multiple damage-repair cycles generally increase the yield stress and reduce the ductility of the steels. The Charpy V-notch fracture toughness of A7 and A36 steel beams repaired with maximum heating temperature (Tmax) equal to 650°C was lower than the fracture toughness of the corresponding undamaged steels. The CVN fracture toughness of A588 steel beams repaired with Tmax equal to 650°C and the A36 steel beam repaired with Tmax equal to 760°C was higher than the fracture toughness of the corresponding undamaged steels. Material specimens that were removed from locations closer to the flange-web interface consistently had lower fracture toughness and ductility.

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