Impact of Local Concrete Crack on the Prestressed Steel Stress Corrosion Cracking

Abstract:

The impact of local concrete crack on the prestressed steel stress corrosion sensitivity is studied with the SSRT, SEM and other methods. The result shows that, the local concrete crack will increase the prestressed steel stress corrosion sensitivity. The formation of stress corrosion microcracks on the metal surface below the crevice is based on two mechanisms: one is the pitting corrosion nucleation mechanism caused due to Cl^-, and the other is the non-pitting corrosion nucleation mechanism caused due to the film rupture. Once the initial stress corrosion microcrack is formed on the metal surface in the crevice, the interior of microcrack will be in the anodic polarization state due to the effect of the electric field of anodic polarization in the crevice, the metal in the crack will continue to be corroded, and the crack will expand. Moreover, due to the anodic dissolution reaction in the crack, the Fe (OH)₃ and Fe₂O₃ films will be formed on the side wall of the crack, and if the nonmetallic slag inclusions and other defects exist on the side wall of the crack, the origin of secondary crack will be formed here, and the intergranular secondary stress corrosion microcrack will be produced.

• Periodical: Advanced Materials Research (Volumes 941-944)
• Pages: 1394-1397
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.941-944.1394
• Online since: June 2014
• Authors: Qi Lei Sun, Ze Rui Liu, Chu Qiao Liu
• Keywords: Local Concrete Crack, Prestressed Steel, Simulative Concrete Pore Solution, Slow Strain Rate Tension Test (SSRT), Stress Corrosion Cracking (SCC)

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