Problems in reinforced concrete can be listed as deterioration, cracking, spalling, hydration, chlorides and sulfate attack, alkalinity, carbonation, and honeycomb. The visible cracks in concrete and crack widths are signs of an element in distress. These cracks are developed from excessive shrinkage, creep and thermal expansion. In the case of steel members, we can also experience lateral buckling, shear deformation, and excessive deflection. For this reason restoration and restauration of structural elements subjected to excessive loading, poor maintenance and deteriorated elements from severe weathering can lead to major problems. For this reason it is critical to design an appropriate infrastructure strengthening method which can be resolved using conventional methods or with the use of fiber reinforced polymer composites (FRP) to provide a flexural and shear upgrade and prolong service life in the structure enhancing the safety of the structural elements. The rehabilitation and retrofit of structures using conventional methods include section enlargement, bonding plates and overlays. This is referred as a passive strengthening technique.

The other alternative of rehabilitation and retrofit of structures is using FRP strengthening with FRP laminates and/or FRP bars for increasing the flexural moment capacity, shear force upgrade and confinement of columns with FRP wraps. These methods will ensure a longer concrete durability, permeability and crack arrest.