Mike..I am restoring a 20's large car portico over the entance to a prarie
school main house. It ( the portico ) was a single pour of concrete; using
large size aggregate for the interior; and the finish work was excellent;using
very fine grain sand and mimics a buff limestone. The corners of the portico
have taken on water badly through a leaking roof; causing the soffit; to spall
and crack with what I think are cloride or calcium hardened drips; exposing
the rusted rebar on both corners. M y plan is to expose as much of the rebar
as possible ; grind it and paint it(rustoleum) and then patch to match the
orginal....then clean the entire portico...what can you recomend  for me ..I
have samples..but basically its a buff limestone; that is slightly warm in
color and very fine grained. I start next week ..Mike