Active strengthening of beams and slabs using steel profiles

Abstract

A technique of reinforcing beams and slabs consists in the arrangement of metal profiles under the elements to be reinforced and challenged to them.

 In the vast majority of cases this reinforcement is conceived as passive: the beams do not come into load as long as the actions on the reinforced element are not increased, or make it slightly and quantitatively difficult to control by challenging with metal wedges.

 An alternative is an active approach: to introduce forces (e.g. by means of jacks, threaded bars, etc.) between the profile and the element to be reinforced, and subsequently challenging the steel beam to the part at the points of introduction of the forces, maintaining the predeformation obtained in the steel element by mortar, metal limestones, etc. The reliability of the calculation of displacement in metal elements allows a thorough control of the forces introduced, both when reinforcing and throughout the life of the structure, by monitoring the displacements in the steel element during the process.

 This work sets out examples of the application of this technique, which show basic technical aspects to consider in this type of reinforcements both in the design and in its subsequent execution and control.