Surface preparation includes thorough removal of all damaged, cracked, incompatible or contaminated layers of the structure. Various technologies are used for that, from manual chipping off of the concrete through pneumatic hammers, milling, sanding, shot peening to high-pressure water jet. The choice of technology depends on particular conditions, and that particularly on the shape and dimensions of the structure, type of the structure and scale of damage of the concrete, requirements related to the thickness of the removed layer and the quality of the prepared surface.
One of the most suitable and today most frequently used methods of surface preparation is high-pressure water jet, which very efficiently removes the damaged parts of the structure and does not damage the deeper good layers. With this technology the secondary contamination of the structure with dust does not occur. High-pressure water jet can be modified for deep removal of the concrete (concentrated into one thin jet), or for surface cleaning (diffused on rotary or swivel head into a beam).
Surface preparation ends with preparation of cohesive, clean and appropriately rough surface, to which to which new layers adhese well.