Information required and regulation for the technical design
When dealing with a concrete repair, strengthening and/or protection project, it is essential to rely on specialists in these areas, thus overcoming the error of believing that any professional without the appropriate specialisation can design this type of work.
The professional in charge of the technology design must have not only the appropriate theoretical training but also the practical experience acquired from working on sites with similar problems. This person (or persons) must be able to study the structure as a whole, not only the damaged element, in order to adequately assess the overall behaviour of the construction.
It is also very important that the team responsible for drafting the technology design is a multidisciplinary team, whose members should include specialists in different fields, such as structural engineers, chemists, geotechnicians, topographers, etc. The number of specialists required, and their fields of expertise will depend on the damage observed and its origins.
It should be noted that a good concrete repair, strengthening and/or protection technology design will depend largely on whether the inspection and diagnosis has been performed correctly.
With the data obtained from the inspection, a diagnosis is made of the state of the structure or concrete element and, subsequently, on the basis of this diagnosis, solutions are designed and chosen. Once this decision has been made, the project is drawn up.
Information required for the technical design
To elaborate the technical design in the most reliable way possible, the following information will be required by the designer(s):
Scope of the repair
The scope of the intervention must be stated very clearly: restore the structure to its initial state, repair minor defects, extend the service life, etc.
At all events, repairs must be carried out following the standard EN 1504. Moreover, local technical regulations must also be applied, e.g., in Belgium, PTV 560-01 of the BCCA (Belgian regulation) must be considered.
Pathologies
The typical pathologies that can be found in concrete structures are the following:
Severity of the damage
To determine the severity of the damage it is necessary to determine the following items:
• Surface exposure class and orientation of damaged surfaces
• Cover and condition of reinforcements (with potential measurements)
• Concrete’s minimum adhesion strength
• In cases of chloride presence, the concentration behind the reinforcement, at different depths.
Extent of the damage
The measurements described in the sections above need to be performed at different locations (orientation/exposure) so that it is possible to estimate the extent of the damage.
Regulatory framework and recommended bibliography
• The execution of concrete repair should always be done in accordance with the EN 1504 European standard.
• Repairs of concrete affected by carbonation should be conducted in accordance with local standards in each European country (for example, BCCA prescription PTV 560-01 from Belgium).
• For repairs of chloride-infected concrete, the local standards should be followed. In the absence of these national standards or if more guidelines are needed, for example, the FEREB recommendations for the treatment of chloride damage are recommended.
