Chloride Content in Segments of the Zilwaukee Bridge

Cores were removed from segments as part of the fifth engineering inspection of the I-75 Zilwaukee Bridge, which started in September 2005. Coring was done to perform an invasive post-tensioning inspection. This was the first time cores had been removed from segments and provided the opportunity to determine chloride contents of the concrete segments. The average water soluble chloride content just below the latex concrete wearing surface is 0.25 lb/yd3, while the average chloride content about 7 in. below the bottom of the latex concrete wearing surface is around 0.15 lb/yd3. If the chloride content at 7 in. below the bottom of the latex concrete surface is considered background chloride, then there is an apparent ingress of chloride into the segment concrete through the latex concrete wearing surface. While the chloride content is well below the corrosion threshold of 1.2 lb/yd3, it is troublesome. The source of the chloride is not clear since the cores were taken well within the ends of the bridge and deicing salts are not used on the bridge.

• Record URL:
  • https://mdotjboss.state.mi.us/SpecProv/getDocumentById.htm?docGuid=14edbf38-a97a-46ac-8697-2a0793ff8e7d
• 
• Corporate Authors:

  Michigan Department of Transportation

  Construction and Technology Division, P.O. Box 30049
  Lansing, MI  United States  48909
• Authors:
  • Till, Roger
• Publication Date: 2007-5

Language

• English

Media Info

• Media Type: Web
• Features: Figures; Tables;
• Pagination: 11p

Subject/Index Terms

• TRT Terms: Chloride content; Concrete curing; Concrete structures; Core samples; Latex; Posttensioning; Segmental construction; Wearing course (Pavements)
• Identifier Terms: Zilwaukee Bridge
• Subject Areas: Bridges and other structures; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01115119
• Record Type: Publication
• Report/Paper Numbers: R-1491
• Files: TRIS, STATEDOT
• Created Date: Nov 25 2008 7:31AM