Bi-Directional Application of Carbon Fiber Reinforced Polymer (CFRP) with CFRP Anchors for Shear-Strengthening and Design Recommendations/Quality Control Procedures for CFRP Anchors

The Texas highway system is handling larger volumes of traffic and heavier loads than were expected when many bridges were designed. It may be necessary to reroute some loads to avoid overloading bridges of questionable strength. Texas bridges are largely constructed with pre-stressed concrete beams. Carbon fiber reinforced polymer (CFRP) strengthening to repair damage in critical locations or to remedy insufficient capacity for permitted overloads would be a valuable addition to structural preservation and life extension techniques. The objective of the study is to demonstrate the feasibility of using bi-directional CFRP for shear strengthening of large bridge I and U-beams. This project is an outgrowth of project 0-6306 in which it was demonstrated that uni-directional CFRP strips and CFRP anchors could be used to improve the shear strength of reinforced concrete elements. The prime objective of that study was to evaluate the role of CFRP anchors. The tests showed that without anchors, the CFRP strips debonded and there was no significant improvement in the shear capacity. With CFRP anchors, it was possible to achieve a 40-50% increase in shear capacity. Tests of four 54 inch deep I-beams with both uni-directional and bi-directional CFRP strips indicated that the use of bi-directional strips led to significantly greater increases in shear capacity. It would not have been possible to strengthen the I-beams without the use of anchors to prevent debonding of the CFRP at reentrant corners of the cross section. Because the data on the bi-directional layout of CFRP was limited, additional work is needed to understand the behavior of the CFRP in strengthening thin webs subjected to large shear forces. Since the anchor installation is a key element of the strengthening technique, there is a need for quality control procedures to make sure that the materials are used properly and the installation meets the design requirements. At present there are no quality control procedures available for CFRP anchors.

Language

  • English

Project

  • Status: Completed
  • Funding: $349640.00
  • Contract Numbers:

    0-6783

  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Jensen, Darrin

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Sanchez-Silva, Mauricio

  • Start Date: 20150430
  • Expected Completion Date: 0
  • Actual Completion Date: 20151231
  • Source Data: RiP Project 39934

Subject/Index Terms

Filing Info

  • Accession Number: 01569100
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-6783
  • Files: RiP, STATEDOT
  • Created Date: Jul 1 2015 2:46AM