International Concrete Abstracts Portal

Title: Corrosion Resistance of Concrete Incorporating Supplementary Cementing Materials in a Marine Environment

Author(s): Andrew Fahim, Edward G. Moffatt and Michael D.A. Thomas

Publication: Special Publication

Volume: 320

Issue:

Appears on pages(s): 18.1-18.14

Keywords: chloride ingress, corrosion, corrosion monitoring, marine environment, servicelife modeling, supplementary cementing materials, durability

Date: 8/1/2017

Abstract:
This paper presents results obtained from steel-reinforced concrete specimens retrieved after 25 to 27 years of exposure in a marine environment. The specimens included mixtures with various SCM blends (25% fly ash, 10% silica fume and 50% slag), as well as a mixture without any SCM, all at a W/CM of 0.50. Testing included chloride-ion depth determination, rapid chloride permeability test, bulk electrical resistivity test and electrochemical corrosion-monitoring. The chloride profiles revealed that SCM incorporation leads to a significant decrease in chloride-ion penetration, which was supported by rapid chloride permeability and bulk electrical resistivity tests. Electrochemical corrosionmonitoring showed passivity for all reinforcements at a cover depth of 70 mm or more for specimens incorporating SCMs, while for specimens not containing SCMs, all reinforcements, up to a cover depth of 140 mm, showed active corrosion. Finally, it was found that the reinforcement corrosion rate in SCM concrete was significantly lower than that for portland cement concrete.