This is what proper preparation looks like for STR Mortar CI. These are precast support columns on a parking structure in Boise, ID that were showing signs of failure due to water infiltration causing oxidation of the rebar. The contractor cut the edges of the repairs and exposed the rebar with a chipping hammer. He then sand blasted all the rust off the existing rebar. He caught it very early and as a result there was very little degradation of the steel.
STR Mortar CI