Corrosion inhibitor for steel-reinforced concrete

A composition for protecting steel-reinforced concrete against corrosion of the steel reinforcement, wherein the composition comprises, as a component A, at least one organosilane or organosiloxane of the formula (I)

• R—SiR1x(O)yR2z (I),
• where
• R is a linear or branched alkyl group having from 3 to 20 carbon atoms;
• R1 is a linear or branched alkyl group having from 1 to 4 carbon atoms;
• R2 is a linear or branched alkoxy group having from 1 to 4 carbon atoms or a hydroxy group, where groups may be identical or different;
• x is 0, 1 or 2;
• y is from 0.0 to 1.5;
• z is 0, 1, 2 or 3;
• and
• (x+2y+z)=3, wherein
• the composition is an oil-in-water emulsion;
• and
• an oil phase of the oil-in-water emulsion comprises at least one of the component A, a component B, a component C, and a component D, where
• the component B comprises at least one aminosilane or aminosiloxane of the formula (II)
• R42N—(R5—NR)a—R6—Si(R7)bOc(OR8)d (II)
• where
• R4 is a hydrogen atom or a linear or branched alkyl group having from 1 to 20 carbon atoms, and groups R4 are identical or different;
• R5 is a linear or branched alkylene group having from 1 to 20 carbon atoms;
• R6 is a linear or branched alkylene group having from 1 to 20 carbon atoms;
• R7 is a linear or branched alkyl group having from 1 to 4 carbon atoms;
• R8 is a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms, and groups R8 are identical or different;
• a is 0, 1, 2, 3 or 4;
• b is 0, 1 or 2;
• c is from 0.0 to 1.5;
• d is 0, 1, 2 or 3;
• and
• (b+2c+d)=3;
• the component C comprises at least one carboxylic acid or salt of a carboxylic acid;
• and
• the component D comprises at least one aminoalcohol of the formula (III)
• HO—CH2—CH2—NR92 (III)
• where
• groups R9 are identical or different;
• and
• R9 is a hydrogen atom or a linear or branched alkyl group having from 1 to 20 carbon atoms.