Surface Preparation

Surface texturing to facilitate cathodic protection on bridge crossbeam

Substrate texturing

Surface preparation—the process of removing deteriorated or contaminated concrete and roughening and cleaning a substrate to enhance bond of a repair material or protective coating. Surface preparation is the process by which sound, clean and suitably roughened surfaces are produced on concrete substrates. This process includes the removal of unsound concrete and bond-inhibiting films, strength verification, opening the pore structure, and establishing profiles suitable for the application of the specified protective system. Most coating or sealing projects will have unique conditions and special requirements that must be evaluated to determine which method(s) will best meet the engineers’ and clients’ objectives.

Over the past 7 years on the motorway structures around Birmingham, we have trialled several methods to come up with a system that removes the smooth layer of concrete to enable a cathodic protection system to be placed on the structure and then to be covered in spray concrete producing a superior bond to the concrete prepared by HP water underneath.

Trident uses the following list to aid the selection process and ensure we meet the individual requirements of the client for each specific project:-

  • Substrate condition: The strength of the substrate and the presence of unsound or bond-inhibiting materials help define the nature and volume of preparation needed.
  • Client requirements: Noise, vibration, dust, and water are effects generated by various preparation methods. The owner’s need for uninterrupted use of the structure, concerns about operating environment or property damage potential will limit the choices.
  • Material requirements: Surface preparation requirement will vary with the protective coating system selected. The properties and application requirements of the selected system should be determined before or during this phase.
  • Application conditions: Generation of slurries, or water may require containment and safe disposal. Mechanical ventilation, available power sources, access and minimum clearance will affect surface preparation decisions.