Feasibility of Using Shape Memory Alloys as Fiber Reinforcement in Concrete

Serviceability and post-event functionality of reinforced concrete bridge structures is greatly influenced by concrete durability, resistance to cracking and deformation recovery. Steel fiber reinforced concrete displays improved toughness and resistance to cracking. Plastic deformations of steel fibers provide significant energy dissipation. Deflection hardening behavior of steel fiber reinforced concrete mixtures leads to tighter cracks, which inhibits the penetration of harmful solutions into the concrete. However, steel fibers experience permanent deformations upon yielding and cannot provide self-centering and crack-closing properties. In this study, the use of randomly distributed shape memory alloy (SMA) fibers in concrete is studied. Five types of beam specimens with the dimensions of 76 mm × 76 mm × 292 mm are prepared for flexural tests. The first beam specimen is a plain concrete beam that serves as benchmark. The second specimen is a steel fiber reinforced concrete beam and includes 0.6% of steel fiber by volume. For the other specimens, 25%, 50% and 100% of steel fibers respectively are replaced with the NiTi SMA fibers. The SMA fibers possess a roughened surface for improved bond behavior. Three point bending tests are conducted on all specimens under cycling loading. An acoustic emission system was used to determine energy release levels during concrete cracking and fiber pullout. An optical Digital Image Correlation method is also used to measure full-field deformations and track the damage evolution on the surface of the specimens. Test results are analyzed in terms of tensile strength capacity, mid-span deflection, and crack width for each specimen.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFN10 Standing Committee on Basic Research and Emerging Technologies Related to Concrete.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Khakimova, Evelina M
  • Sherif, Muhammad M
  • Tanks, Jonathon D
  • Ozbulut, Osman E
  • Harris, Devin K
  • Ozyildirim, Celik
• Conference:
  • Transportation Research Board 95th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2016-1-10 to 2016-1-14
• Date: 2016

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 16p
• Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Deflection; Fiber reinforced concrete; Repeated loads; Tensile strength
• Uncontrolled Terms: Beam specimens; Bending tests; Crack width; Shape memory alloys
• Subject Areas: Bridges and other structures; Highways; Materials;

Filing Info

• Accession Number: 01594363
• Record Type: Publication
• Report/Paper Numbers: 16-2483
• Files: TRIS, TRB, ATRI
• Created Date: Mar 22 2016 10:15PM