Title: Corrosion Protection Shield of Steel Bars, Due to Steel Fibers in Concrete

Author(s): Abdullah Keyvani Someh, Noboru Saeki and Takenori Notoya

Publication: Symposium Paper

Volume: 171

Issue:

Appears on pages(s): 227-248

Keywords: Chlorides; corrosion; galvanized materials; steels; tests.

DOI: 10.14359/6099

Date: 8/1/1997

Abstract:
Severe deterioration caused by corroding reinforcing steel in concrete structures is a major concern in the maintenance of safe and reliable infrastructure. The corrosion behavior of steel fibers and steel bars under two different aggressive conditions of modified ferroxyl gel reagent and wet-dry salt spray are described. In general, the results in the aggressive gel environment indicate that when steel fibers and steel bars were contacting each other, the initiation of corrosion in the steel fibers became considerable. When the steel fibers were electrically connected to the steel bars, the steel fibers tend to become the anode while the steel bars tend to become the cathode. The corrosion initiation, its propagation and the growth of the corrosion zones occurred in the steel fibers. The steel bars, set in the cathode zone, were protected by the surrounding steel fibers which formed a corrosion protective shield. This galvanic protection behavior by steel fibers was clearly observed in ferroxyl transparent gel. To generalize the galvanic protection behavior of steel fibers in the gel environment, the behavior of reinforced concrete specimens under an accelerated aggressive environment with both a no-fiber and fibrous concrete matrix were investigated. For this purpose, galvanized steel fibers were used. Corrosion phenomenon in the galvanized steel fibers contacting steel bars showed a sacrificial role of fibers in protecting the steel bars. No corrosion of the embedded steel bars occurred in the steel fiber-reinforced concrete matrix, while corroded steel bars occurred in the no-fiber reinforced concrete beam, thus confirming the merit of galvanized steel fibrous matrix as a protection shield to inhibit corrosion of reinforced concrete members.