Using locally pre-stressed reinforcing bars to restore the capacity of severely damaged steel beams

This paper investigates the behaviour of damaged steel beams repaired using locally pre-stressed reinforcing steel bars. Regular reinforcing bars are welded to the beam’s web at both ends and then pretensioned using a manual screw jack to increase the effectiveness of the repair. Six beams with different bar diameters and levels of pre-stress were repaired and tested under three-points bending. Results showed that the level of pre-stress controlled the beams’ stiffness, while restoration of their ultimate load-carrying capacity was governed by the bar size. Significantly higher repaired capacities were achieved by this method than by other published methods used for the strengthening of steel beams.