Dual-Function Near-Surface Mounted Titanium Alloy Bars for Structural Strengthening and Cathodic Protection of Reinforced Concrete Infrastructure

Details

• Creators:
  Higgins, Christopher
• Corporate Creators:
  Oregon State University. Department of Civil Engineering
• Corporate Contributors:
  CREATE - Coastal REsearch And Transportation Education ; United States. Department of Transportation. University Transportation Centers (UTC) Program ; United States. Department of Transportation. Office of the Assistant Secretary for Research and Technology
• Subject/TRT Terms:
  Cathodic Protection Corrosion Fiber Reinforced Concrete Infrastructure Near-surface Mounted Reinforcement Titanium Alloys
• Publication/ Report Number:
  2301-9
• DOI:
  https://doi.org/10.5281/zenodo.18735817
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final, 9/1/2023- 6/01/2026
• Corporate Publisher:
  CREATE - Coastal REsearch And Transportation Education
• Abstract:
  Corrosion-induced deterioration of reinforced concrete (RC) transportation infrastructure frequently necessitates rehabilitation to address both structural capacity deficiencies and ongoing reinforcement corrosion. These challenges are typically treated independently, with structural strengthening systems restoring capacity and impressed current cathodic protection (ICCP) systems used to mitigate corrosion. This separation increases construction complexity and limits the long-term efficiency of rehabilitation efforts. This research develops and validates a dual-function rehabilitation system that integrates structural strengthening and corrosion protection into a single near-surface mounted retrofit (NSMR) solution. The system employs high-strength titanium alloy bars (TiABs) as near-surface mounted reinforcement while simultaneously using those bars as ICCP anodes to protect embedded steel reinforcement. A key enabling component is a specially developed electrically conductive structural grout (ECSG) that provides both mechanical bond and electrical connectivity between the TiABs, concrete substrate, and protected reinforcement. The research program combines electrochemical and structural performance evaluations. Electrochemical testing, including material characterization, small-scale prism experiments, and large-scale beam specimens subjected to active corrosion, demonstrated that TiABs installed with ECSG function effectively as ICCP anodes, achieving stable operating currents, predictable polarization behavior, and compliance with accepted cathodic protection performance criteria. Structural tests included bond (pullout) experiments and large-scale flexural and shear beam tests of specimens representative of vintage RC bridge construction practices. Results confirmed that ECSG-bonded TiABs satisfy development length requirements, restore flexural and shear capacity, and maintain predictable failure modes consistent with established NSMR design practices. Collectively, the results demonstrate that near-surface mounted TiABs can be deployed as a true dual-purpose system, simultaneously restoring structural capacity and enabling long-term corrosion protection. This report synthesizes the findings into a system-level assessment and provides a foundation for future development and implementation of integrated strengthening and preservation strategies for aging transportation infrastructure.
• Format:
  PDF
• Funding:
  69A3552348330
• Collection(s):
  Federal Highway Administration
• Main Document Checksum:
  urn:sha-512:109d6b38254a64bd7f1bb00c856c80142b825a24a30137298cc9e4d56d84523df90e4ce8f2b184abd7c5605c02089cb58d9b90b31b93bb3e0abbfc2e7ea81537
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/92492/dot_92492_DS1.pdf
• File Type:
  [PDF - 3.99 MB ]