The structural design and thus the production of structural elements made of reinforced concrete is based on forces and loads current in codes of the time. However, during the service life of a structure,
various circumstances may require that the service loads are changed due to:
Modification of the structure
Aging of the construction materials
Deterioration of the concrete caused by reinforcement corrosion
Earthquake design requirements; fire design changes
Upgrading of building codes relating to load bearing capacity or service loads etc
The consideration of the actual loads resisted by a structure is a necessary prerequisite for the development of a comprehensive rehabilitation concept. Basically, the methods available for the structural strengthening of structural elements made of reinforced concrete are as follows:
Application of cast or sprayed concrete with additional reinforcement
Placing of additional reinforcement in slots cut in the concrete
External post-tensioning
Installation of supports or additional bearing members
Steel plate bonding to increase shear or flexural capacity
An alternative to these traditional methods of strengthening is the use of Fibr Reinforced Polymer (FRP) composites.
