Assessment and Shear Strengthening of Existing Cast-in-Place and Precast Concrete Bridge Girders

Details

• Creators:
  Grayson-Wallace, Brendan ; Aljasar, Ahmed ; Vasquez, Emmanuel ; Kunnath, Sashi K. ; Cheng, Dawn ; Bolander, John
• Corporate Creators:
  University of California, Davis. Department of Civil and Environmental Engineering
• Corporate Contributors:
  California. Department of Transportation
• Subject/TRT Terms:
  Bridge Decks Cast In Place Concrete Fiber Reinforced Concrete Shear Reinforcement
• Publication/ Report Number:
  CA 25-3303
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report (2019 - 2023)
• Corporate Publisher:
  California. Department of Transportation
• Abstract:
  This research study investigated the feasibility of two shear-strengthening techniques to assess their effectiveness in enhancing the shear capacity of existing reinforced concrete girder bridges. The first scheme consisted of using Near-Surface-Mounted (NSM) bars while the second scheme comprised Partially Embedded Bars (PEB) in the web of the girder. First, a preliminary series of pull-out tests were carried out to examine various options to enhance the anchorage and/or bond of the NSM bars and PEB to the existing concrete. In the case of the NSM approach, none of the anchorage improvement techniques resulted in significant strength gain. For PEB, specimens with sand-coated CFRP bars bonded with the epoxy performed better than the specimens with other strengthening materials. Next, a finite element (FE) study was carried out using the commercial software ATENA to investigate the two strengthening schemes. The model was validated by comparing the simulated response to the findings from the control tests. The validated model was then used to predict the shear enhancement due to the two proposed strengthening schemes. The experimental program comprised three-point load bending tests to failure of full-scale RC T cross-section girders strengthened in shear using the two strengthening schemes. Findings from the experimental study indicate that NSM is not likely to be effective for large-scale girders where 3D effects cause failure to occur locally due to local side cover detachment. Results from the next phase of testing demonstrated that the PEB method is an effective shear-strengthening technique. An increase of 53% and 30% was observed in the shear capacity of the strengthened specimen compared to the control specimen. Hence, it is recommended that shear-deficient reinforced concrete girders be strengthened with partially embedded bars as added shear reinforcement.
• Format:
  PDF
• Funding:
  65A0732
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:3bd6557a128ccb27a11524698b660b2cd3e6f395199a7bfc67b0b1dcce5fe830e9802d4a58b07c98cce86b4c4a3f1526ed6e2ba156480375b9a03eb6c5b13815
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/85016/dot_85016_DS1.pdf
• File Type:
  [PDF - 8.03 MB ]