The 11 Principles & Methods Concerning Concrete Defects
The repair and protection of concrete structures requires relatively complex assessment and design. By introducing and defining the key principles of repair and protection, EN 1504-9 helps owners and construction professionals to fully understand the problems and solutions throughout the different stages of the repair and protection process. The eleven principles of concrete repair and protection according to EN 1504-9 are:
The principle is to keep the concrete dry by reducing its permeability by closing up pores and cracks.
The principle of controlling moisture with acceptable levels using coatings and membranes.
Repairing or replacing concrete using a variety of mortars.
Replacing lost strength or increasing strength by adding steel, additional reinforced concrete or Fibre Reinforced materials.
Replacing lost concrete or providing additional cover and protection.
Application of surface protection to improve resistance to chemical attack.
Using mortars or concrete to replace contaminated concrete. Also techniques for re-alkalisation and chloride extraction.
Using coatings and protective systems to reduce the level of moisture in the concrete thereby increasing the electrical resistivity of the concrete and reducing the potential for corrosion.
Restricting the access of oxygen to the cathodic site by coating the steel.
Cathodic protection manages the output of current through the steel to channel currents to specific anodic sites. This may be done using external currents or sacrificial anodes.
Corrosion of the reinforcement is controlled by a complete film formation, using coatings or corrosion inhibitors.