Feasibility of Using Shape Memory Alloys to Develop Self Post-Tensioned Concrete Bridge Girders

Post-tensioned (PT) structural elements are used quite often in bridges due to their ability to span long widths economically while providing an aesthetically pleasing structure. PT systems are also preferred in bridge construction because they greatly increase structural capacities and are fairly easy to implement effectively. Although PT systems provide many advantages for designers and constructors, these systems have raised concerns regarding corrosion of the PT tendons. The degree of corrosion of PT tendons is critical to the structural performance of PT systems and the cost to replace tendons can exceed several hundred thousand dollars per tendon. Shape memory alloys (SMAs) are a class of smart materials that have unique properties such as excellent re-centering ability, good energy dissipation capacity, excellent fatigue resistance, and high corrosion resistance. This project investigates the feasibility of developing self post-tensioned (SPT) bridge girders by activating the shape memory effect of SMAs using the heat of hydration of grout. In particular, the project will investigate the mechanical response of the SMA tendons and the temperature increase due to the heat of hydration of grout. A typical post-tensioning duct will be filled with grout at room temperature to monitor the temperature inside the duct during the grout's hydration. A Type III Portland cement will be used for the grout since the Type III cement has higher heat of hydration than other cement types. Type III cement has also advantages such as faster initial set and slightly less tendency toward bleeding. The grout will be mixed in accordance with the manufacturer's recommendation. Thermocouples will be embedded at several locations within the duct to measure the temperature. A FLIR System T 440 thermography camera with a 320 x 240 pixel infrared imaging resolution will be also used in the experiment. The use of thermography provides comprehensive information regarding the evolution of grout temperature by enabling simultaneous monitoring of a large surface. The variation of the temperature versus time will be examined. This study will serve as a foundation for future analytical and experimental research on self post-tensioned concrete for bridge structures.


    • English


    • Status: Active
    • Contract Numbers:



    • Sponsor Organizations:

      Mid-Atlantic Universities Transportation Center

      Pennsylvania State University
      201 Transportation Research Building
      University Park, PA  United States  16802-4710
    • Performing Organizations:

      University of Virginia, Charlottesville

      Center for Transportation Studies
      P.O. Box 400742, Thornton Hall, D228
      Charlottesville, VA  United States  22903
    • Principal Investigators:

      Ozbulut, Osman

    • Start Date: 20130101
    • Expected Completion Date: 0
    • Actual Completion Date: 20130531
    • Source Data: RiP Project 33485

    Subject/Index Terms

    Filing Info

    • Accession Number: 01470885
    • Record Type: Research project
    • Source Agency: Mid-Atlantic Universities Transportation Center
    • Contract Numbers: DTRT12-G-UTC03, 140735-D
    • Files: UTC, RiP
    • Created Date: Jan 30 2013 1:00AM