YES. IT IS POSSIBLE TO USE EVEN RUST REBAR.RN RN1.CONCRETE WHOSE AVERAGE PH VALUE IS 12.8 HAS ALKALINE REACTION. REINFORCING BARS ARE NOT EASILY CORRODED WITH 2~6×10-6MM PASSIVATION FILM ON THE SURFACE. IN ADDITION, CORROSION OF RUST STEEL BARS DOES NOT CONTINUE INSIDE CONCRETE. RNRN2. AS FOR THE CORRODED STEEL REINFORCEMENT, WHEN CORROSION OCCURS IN ABOUT 1 PERCENT OF STEEL VOLUME, THIS INCREASES BOND STRENGTH. EVEN WITH A LARGER-SCALE CORROSION, RUST HARDLY REDUCES BOND STRENGTH, UNLESS IT IS LOOSE RUST. THE REASON IS BECAUSE THE BONDING OF STEEL REINFORCEMENT DEPENDS ON THE EFFECTS OF NODES, NOT ON THE ADHESIVENESS OF THE SURFACE. HOWEVER, LOOSE RUST MAY HAVE NEGATIVE EFFECTS ON THE BONDING OF REINFORCING BARS AND CONCRETE. RNRNTHEREFORE, THE USE OF RUST STEEL REINFORCEMENT DOES NOT AFFECT THE QUALITY OF CONCRETE STRUCTURES. IN RELATION TO THIS, THE CONCRETE STRUCTURE DESIGN STANDARD (2007) PROVIDES THE SURFACE CONDITION OF REBAR IN CHAPTER 5 AS BELOW:RNRNTHE CONCRETE STRUCTURE DESIGN STANDARD (2007), 5.2.4 SURFACE CONDITION OF STEEL BARSRNWITH THE EXCEPTION OF PS STEEL, THERE IS NO NEED FOR RUST, FRAGMENTS GENERATED FROM THE PROCESSING PROCESS OR THE COMBINATION OF THEREOF TO BE REMOVED, UNLESS THEY FALL SHORT OF THE STANDARDS CONCERNING THE HEIGHT OF NODES AND THE MINIMUM SIZE AND THE WEIGHT OF REBAR IN ACCORDANCE WITH KS D 3504. RN