Active Confinement of Bridge Piers Using Shape Memory Alloys

This project will develop and test a system for the active confinement of reinforced concrete bridge piers using shape memory alloys (SMAs). Work in Stage 1 focuses on evaluating SMA-based materials for the proposed confinement of bridge piers. A material testing program is in progress to determine the stress-strain behavior of concrete cylinders actively confined with SMAs. Two SMA-based products (SMA spirals and hoops) were evaluated for their thermo-mechanical characteristics and effectiveness in enhancing the concrete compressive strength and ductility. The Ni-Ti alloy was used in the first stage of the tests. Results showed that applying the confining pressure using the Ni-Ti SMA wires improved compressive strength and ductility of the concrete cylinders by 30% and 220%, respectively. A new series of tests is underway using a new type of SMAs with enhanced thermal characteristics (NiTiNb). This new SMA will reduce significantly the prestress losses in SMA wires. Work in the second phase of the project will focus on structural testing of bridge columns. A series of quasi-static cyclic tests will be conducted on a number of reduced-scale reinforced concrete bridge columns. The SMA products evaluated and selected in the first phase will be used to retrofit the test columns using active confinement technique. Tests will also include column specimens retrofitted using conventional passive confinement techniques (FRP wraps). The specimens that will be used in these tests are currently being designed and detailed. The effectiveness of SMAs retrofit will be compared with conventional retrofits by evaluating the hysteretic behavior of the tested columns and assessing the amount of damage. The final report will document all data and developments of the SMA-based reinforcement system for bridge columns along with an assessment of the technology for implementation and commercialization.

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:

    Jawed, Inam

  • Performing Organizations:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Start Date: 20090422
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 22079

Subject/Index Terms

Filing Info

  • Accession Number: 01547250
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 20-30, IDEA
  • Files: TRB, RiP
  • Created Date: Dec 4 2014 1:00AM