Title:
Effect of Combining Near-Surface-Mounted and U-Wrap Fiber-Reinforced Polymer Strengthening Techniques on Behavior of Reinforced Concrete Beams
Author(s):
Rahulreddy Chennareddy and Mahmoud M. Reda Taha
Publication:
Structural Journal
Volume:
114
Issue:
3
Appears on pages(s):
719-728
Keywords:
ductility; fiber-reinforced polymers (FRPs); near-surface mounting; U-wrap shear strengthening
DOI:
10.14359/51689443
Date:
5/1/2017
Abstract:
Flexural strengthening of reinforced concrete (RC) beams using near-surface-mounted (NSM) fiber-reinforced polymers (FRP) and U-wrap FRP shear strengthening are two well-established methods. There is a fair chance that the two aforementioned techniques might be mixed in strengthening of RC beams. This research examines the behavior of RC beams strengthened using NSM and U-wrap FRP strengthening. The NSM-FRP flexural strengthening technique is strongly dependent on the performance of bond between the NSM-FRP bar and the surrounding epoxy. Tension rupture of the NSM-FRP bar is highly unlikely, even when a full development length is provided. However, when U-wrap FRP is considered, confinement has shown to improve the bond strength of NSM-FRP bars and marginally increase the flexural capacity of strengthened RC beams. However, the improvement in the bond strength of NSM-FRP bars results in changing the NSM-FRP debonding to an abrupt failure caused by NSM-FRP bar rupture. Special care should be taken in designing RC strengthening combining NSM and U-wrap FRP strengthening.