Title: Use of Anchored Carbon Fiber-Reinforced Polymer Strips for Shear Strengthening of Large Girders

Author(s): William A. Shekarchi, Wassim M. Ghannoum, and James O. Jirsa

Publication: Structural Journal

Volume: 115

Issue: 1

Appears on pages(s): 281-291

Keywords: carbon-fiber reinforced polymer (CFRP); CFRP anchors; reinforced concrete (RC); shear behavior; shear strengthening

DOI: 10.14359/51701092

Date: 1/1/2018

Abstract:
The objective of this research was to investigate the feasibility of increasing the shear capacity of large reinforced concrete girders using anchored carbon fiber-reinforced (CFRP) strips. In an experimental study consisting of nine tests, the effects of unidirectional and bidirectional CFRP layouts, anchored and fully wrapped systems, retrofitting uncracked and precracked sections, and loading conditions on the shear performance of large girders with relatively wide webs were investigated. Test results indicated that CFRP anchors were able to develop the fracture strength of the CFRP strips despite some anchors being placed in flexural tension zones. The unidirectional CFRP layouts were able to improve the shear capacity by as much as 56% while the bidirectional layouts improved the inclined cracking shear load by as much as 22%. Moreover, the measured lower-bound average CFRP fracture strain was found to be significantly larger (0.007) than the maximum permitted effective strain (0.004) currently recommended for design.