The need of rehabilitation and strengthening of concrete structures has increased considerably the last decade. The causes for repair and/or strengthening can be many, but normally change of use, increased demands on the structure, errors in the design or/and construction phase or accidents are governing. Many methods to repair or/and strengthen concrete structures exists such as concrete overlays, shotcrete, external prestressed cables etc.

ADVANTAGE :
External prestressing is a very effective technique for both Existing and new structures.
Many researchers proven that the external prestressing having following advantages:
Profiles of external tendons are easier to check during and after Installation hence, provide the ease of inspection.
External tendons can be removed and replaced if any type problem found.
It usually allows easy access to anchorages, adjustment and control of tendon forces