It is well known that mineral mortars are used to repair concrete. Cement is usually used as a binder for sand and possibly other aggregates, and the mixture sets hydraulically with water. If necessary, additives are added to improve certain properties of the concrete. Cement-bound mortars can be used on wet substrates, - harden only above 0 ºC, - require long setting times - and have low flexibility and low resistance to wear and aggressive media. It is astonishing how little is known about the fact that concrete can also be renovated with mortars whose mineral aggregates are not bound by cement but by synthetic resins. Synthetic resins are probably not considered to have the same properties as concrete, especially in terms of compressive strength. The opposite is true, as synthetic resin-bonded mortars sometimes have significantly higher strengths than concrete itself and also exceed most of the other performance characteristics and properties of concrete.