Advancements in shear strengthening of prestressed concrete I-girders using fiber reinforced polymers

Abstract

<p>A number of attempts were made by different researchers in the last couple of decades to strengthen prestressed concrete (PC) I-girders in shear using externally bonded FRP (fibre reinforced polymer) reinforcement. The unanimous observation reported in the literature is the early debonding of FRP shear reinforcement around the internal angles of the I-section. Because of this undesirable phenomenon, the strength of the FRP is utilized inefficiently. This paper gives an overview of the techniques utilized in the past and their relative performance in order to develop a rational solution to the debonding problem, particularly for I-sections. The anchoring techniques used in the past includes different types of FRP anchors as well as mechanical anchors to protect FRP shear reinforcement from debonding on the I-section. It can be concluded that the definite solution to the debonding problem on I-sections has not been obtained yet. This is because of the complex failure modes of FRP shear reinforcement and PC I-girders.</p>

Shear strengthening of precast prestressed I‐girders using carbon fiber reinforced polymers and in‐fill concrete blocks

“…A state-of-the-art overview is provided in. 15 Earlier studies, to postpone early debonding of I-shaped shear strengthening, have used different types of anchorages such as horizontal CFRP sheets over the vertical/ diagonal sheets, 10,12,14,16,17 mechanical anchors, 12 CFRP spike anchors, 13,18 and CFRP strips embedded in a groove cut at the web-flange corner. 16 More details on such anchorage systems used in externally bonded CFRP systems can be found in.…”

“…Only a limited number of studies are available on shear strengthening of prestressed concrete (PC) I‐girders. A state‐of‐the‐art overview is provided in 15 . Earlier studies, to postpone early debonding of I‐shaped shear strengthening, have used different types of anchorages such as horizontal CFRP sheets over the vertical/diagonal sheets, 10,12,14,16,17 mechanical anchors, 12 CFRP spike anchors, 13,18 and CFRP strips embedded in a groove cut at the web‐flange corner 16 .…”

Shear Strengthening of Precast Prestressed Bridge I-Girders Using Shape Memory Reinforcement

“…A similar shear strengthening approach for I-girders has also been applied in another large scale study [11], and was combined with flexural strengthening by means of prestressed CFRP. For a further state-of-the-art overview on shear strengthening of I-girders using CFRP, reference is made to the comprehensive study [12].…”