The use of post-tensioning permits the construction of economical, long-span bridges. In recent years, repair and maintenance of post-tensioned bridges have gained importance in light of a few instances of serious tendon degradation (Corven Engineering 2001). Guidance documents exist for early life stages of these structures: the AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications identify the minimum bridge design requirements, while the Federal Highway Administration’s Post-Tensioning Installation and Grouting Manual (2013) provides guidance on construction practices. Practices aimed to improve post-tensioned structures’ durability over the long-term are qualitatively discussed in a few guidance documents, such as fib’s Bulletin 33. However, very limited information is available to guide bridge owners on how to maintain existing structures, or, more specifically, to repair degraded post-tensioned structures. While bridge owners approach issues requiring remediation on a case-by-case basis, identification of current practices and knowledge transfer across states could improve structure integrity and reduce maintenance and repair efforts.
The purpose of this synthesis is to gather information on the practices used by bridge owners to repair and maintain post-tensioned bridges. The goal is to further facilitate knowledge transfer across state DOTs, aiding bridge owners in the identification of repair practices that are working.
The report should include the following (not an exhaustive list):
- design details
- repair methodologies
- maintenance documentation. The study will cover practices about the following post-tensioned bridge elements:
- bridge superstructure elements, including externally post-tensioned and internally post-tensioned members
- caps and pier elements
Information will be gathered by literature review which identifies the most relevant examples, techniques and conditions under which consistent results are achieved. Surveys and/or interviews of the state DOTs and selected contractors, and a minimum of five case examples shall be included. Case examples should focus on corrective actions and should consider:
- Owner’s existing policies, specifications;
- Recent remediation actions and after-action feedback from the owner’s perspective;
- Guidance documents, as they exist.
American Association of State Highway and Transportation Officials (AASHTO). (2017). AASHTO-LRFD Bridge Design Specifications. American Association of State Highway and Transportation Officials, Washington D.C.
Corven Engineering, Inc. (2001). “Mid-Bay Bridge Post-tensioning Evaluation: Final Report.”
Federal Highway Administration (FHWA). (2013). “Post-tensioning Installation and Grouting Manual.” Federal Highway Administration, Washington D.C.
Fuzier, J-P., Ganz, H-R., Matt, P. (2005). “Bulletin 33: Durability of post-tensioning tendons.” fédération internationale du béton (fib). Sprint-Digital-Druck, Stuttgart.
First Panel: September 11, 2019, Washington, DC
Teleconference with Consultant: