Title: Bond Behavior of Corroded Strand in Pretensioned Prestressed Concrete Beams

Author(s): Lei Wang, Ju Yi, Jianren Zhang, Royce W. Floyd, and Yafei Ma

Publication: Structural Journal

Volume: 115

Issue: 6

Appears on pages(s): 1803-1812

Keywords: bond behavior; bond stiffness; bond strength; failure mode; strand corrosion

DOI: 10.14359/51706892

Date: 11/1/2018

Abstract:
Bond behavior between corroded steel strand and concrete in pretensioned prestressed concrete beams was investigated experimentally in this study. Nine pretensioned beams were tested to study the effects of corrosion on global force-slip response, bond strength, and failure mode. Experimental results showed that strand corrosion loss less than 5.25% improved the bond stiffness. Strand corrosion significantly decreased the bond stiffness when the corrosion loss was greater than 8.08%. The ultimate bond stress didn’t degrade with corrosion progression until the corrosion loss was greater than 4.4%. The failure mode of the beam changed from concrete crushing to strand fracture when the corrosion loss and crack width exceeded 5.25% and 0.31 mm (0.013 in.), respectively. Compared with existing data on tensile degradation behavior of corroded steel prestressing strands, corrosion deteriorated the tension strength of strands more significantly than the bond strength for corrosion loss less than 9.24%.