Corrosion-Resistant, Structurally Reinforced Thermal Spray Coatings for In-Situ Repair of Load Bearing Structures

This project was aimed at developing and demonstrating the feasibility of in-situ reclamation of corroded components in load bearing infrastructures (such as bridges) providing robust corrosion protection with high-velocity thermal spray coating. Work in Stage 1 focused on the mechanical behavior of the optimized thermally-sprayed reclaimed steel. Initial efforts used Fe or Ni as the reclaimant material deposited using the high velocity oxy-fuel (HVOF) thermal spray process. Process optimization with in-situ monitoring of residual stresses demonstrated that compressive residual stresses could be achieved in HVOF reclamation material. Mechanical testing to date shows that in almost all cases, the addition of the coating shows load recovery and enhancement in yield stress. This suggests good coupling between the reclaimed material and the parent metal as well as demonstration of load bearing capability of the HVOF coating. Detailed comparisons between Fe and Ni coatings were made. At thin coatings, the Ni deposited ones presented a better performance compared to the Fe-based ones, since they were able to endure excessive loads and displacements without delamination. However, both coatings presented an increased load bearing capacity compared to virgins -uncoated- tensile test specimens. At thick coatings, new spraying parameters were required in order to produce more compressive coatings, as they were showing premature failure. The new compressive Ni coatings presented the highest load bearing capacities, compared to all coatings and virgin tensile specimens. The composite repaired structure with Nickel overlay also shows excellent corrosion resistance. Concurrently, efforts were initiated aimed at understanding of the operative mechanisms on strength reclamation via finite element modeling and experiments. Results to date appear promising and represent a good transition opportunity. The next step in furthering and implementing this technology is consider a larger scale component demonstration as well as future transfer of the Innovations Deserving Exploratory Analysis (IDEA) results into practice. For this active involvement of state departments of transportation (DOTs) is needed and being solicited.

Language

  • English

Project

  • Status: Completed
  • Contract Numbers:

    Project 20-30, IDEA

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Parker, Stephan

  • Principal Investigators:

    Williams, Jon

    Jawed, Inam

  • Start Date: 20110101
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 38678

Subject/Index Terms

Filing Info

  • Accession Number: 01549559
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-30, IDEA
  • Files: TRB, RiP
  • Created Date: Jan 3 2015 1:00AM