Shear behavior of full-scale reinforced concrete T-beams strengthened with CFRP strips and anchors Yungon Kim a , Wassim M. Ghannoum b,⇑ , James O. Jirsa b a Hyundai Engineering and Construction, Seoul, South Korea b University of Texas at Austin, United States highlights  Nine 1220 mm deep T-beams were strengthened in shear using anchored CFRP.  With CFRP anchors, CFRP strips ruptured in all tests.  The effective strain in the CFRP strips was about 1/2 of the fracture strain.  CFRP shear-strength contribution was greater in beams with less transverse steel. article info Article history: Received 17 May 2014 Received in revised form 6 May 2015 Accepted 4 June 2015 Keywords: CFRP CFRP anchor Reinforced concrete Full-scale Shear strengthening abstract Nine tests were conducted on 1220 mm deep T-beams strengthened in shear using Carbon Fiber-Reinforced Polymer (CFRP) strips and CFRP anchors. The use of anchors resulted in most CFRP strips reaching fracture, but not simultaneously. The shear contribution of FRP was larger in beams with less transverse steel reinforcement. Because CFRP and steel reinforcement have different material and bond properties, interactions between the two materials need to be taken into account when determining the shear capacity of a strengthened member. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Carbon Fiber-Reinforced Polymers (CFRPs) can be quickly applied in retrofit or repair applications, with a minimum of func- tional disruption and with virtually no change in the geometry of structural elements. Many studies have been conducted on the application of externally bonded FRP in strengthening reinforced concrete bridge members (NCHRP report 655 [1]). A large number of studies have also been performed to investigate the shear strengthening of structural members using CFRP materials (e.g., [2–7]). NCHRP report 678 [8] provides a comprehensive summary of shear strengthening studies using FRP. The report identifies key parameters affecting the behavior of systems strengthened with FRP based on a database of reported test results. The report high- lights the need for mechanical anchorage of FRP materials to con- crete members so that the full strength of the FRP materials can be utilized. The report also recommends further investigations of the interactions between the internal transverse steel reinforcement and externally bonded FRP shear reinforcement on shear strength of concrete members. Although there have been numerous experimental studies on shear strengthening using FRP materials, relatively few included mechanical anchorage of external FRP to concrete members, and even fewer used CFRP anchors (e.g., [8–23]). Moreover, many pre- vious experimental studies were conducted on specimens that might not represent typical construction practices, such as small-scale specimens, specimens without transverse steel rein- forcement, or specimens completely wrapped with FRP [24]. Anchorage of FRP materials is needed in cases where complete wrapping is not practical, such as in members that include flanges, floor slabs, or bridge decks. CFRP anchors have been proven to develop the full strength of externally applied CFRP strips in shear strengthening applications [18]. In a previous experimental pro- gram conducted by Kim et al. [23], 610 mm deep reinforced con- crete T-beams were strengthened in shear using U-wrapped CFRP http://dx.doi.org/10.1016/j.conbuildmat.2015.06.005 0950-0618/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: ghannoum@mail.utexas.edu (W.M. Ghannoum). Construction and Building Materials 94 (2015) 1–9 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat