PERFORMANCE OF REINFORCING STEEL IN CONCRETE CONTAINING SILICA FUME AND BLAST-FURNACE SLAG PONDED WITH SODIUM-CHLORIDE SOLUTION

This paper describes the performance of steel reinforcement in concrete slabs that were ponded with a 3.4% sodium-chloride solution for a period of 6 months. The concrete slabs were cast using Portland cement concrete with and without silica fume and blast-furnace slag. The concrete cover to steel reinforcing bars ranged from 13 mm to 76 mm. The concrete resistance to chloride-ion penetration was determined according to American Society for Testing and Materials C 1902. The corrosion resistance of the steel reinforcing bars was determined using half-cell potential, linear polarization, and alternating current (AC) impedance techniques. The test results showed that both the silica fume and slag concretes exhibited very low penetrability to chloride ions, with the value of charge passed being less than 1,000 coulombs. All control concretes had the value of charge passed greater than 1,000 coulombs, regardless of the water-cement ratio (w/c). There was no significant corrosion of the reinforcing steel in the silica fume, slag, and control Portland cement concrete with water-cementitious materials ratio of 0.52 after 6 months of ponding with a 3.4% sodium chloride solution. Significant corrosion rates were observed for the reinforcing steel embedded in control Portland cement concrete with w/c > 0.43. As expected, the poorest performance was of the control concrete with a w/c of 0.76, where the corrosion of reinforcing steel was detected, even with a 51 mm concrete cover. There was a good correlation among the test results obtained using the half-cell potential, linear polarization, and AC impedance techniques.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00795743
  • Record Type: Publication
  • Contract Numbers: NSF/GER-9023496-02, CMS-9632407, NSC 84-2211-E-009-14
  • Files: TRIS
  • Created Date: Jul 27 2000 12:00AM