Title:
Hybrid Externally Bonded/Mechanically Fastened Fiber-Reinforced Polymer for RC Beam Strengthening
Author(s):
Usama Ebead
Publication:
Structural Journal
Volume:
108
Issue:
6
Appears on pages(s):
669-678
Keywords:
externally bonded fiber-reinforced polymer; fasteners; mechanically fastened fiber-reinforced polymer; reinforced concrete beams; strengthening
DOI:
10.14359/51683365
Date:
11/1/2011
Abstract:
This study examines a newly developed technique for the flexural strengthening of reinforced concrete (RC) beams. This technique is a combination of the externally bonded (EB) and mechanically fastened (MF) fiber-reinforced polymer (FRP) systems. It features the use of nylon anchors to be inserted inside the concrete prior to installing the fasteners. The hybrid EB/MF-FRP-strengthened specimens showed higher load capacity and post-cracking stiffness than those of the corresponding MF-FRP counterparts. Extending the FRP strips for the entire beam span is necessary for achieving the noticeable enhancement of the load capacity and stiffness with this hybrid EB/MF-FRP system. For such a system, the failure of the strengthened beams is associated with diagonal cracks at the locations of fasteners near the FRP strip ends. These cracks are initiated due to fastener rotation and bearing damage, resulting in a noticeable slip of the FRP strips with respect to the soffit of the beams.