Strengthening of prestressed concrete girders with composites: Installation, design and inspection

Abstract The application of fibre reinforced polymer (FRP) or steel reinforced polymer (SRP) materials to the tension side of a reinforced/prestressed concrete member has been accepted as a strengthening technique to increase the load carrying capacity and in some cases can enhance member serviceability. Proper installation and regular inspection of a composite (FRP or SRP) strengthening system is important since quality of the bond is essential to internally transfer forces. This paper describes an experimental programme conducted to study the behaviour of six prestressed concrete bridge girders, which were tested under static and fatigue loading conditions. The test results were combined with the results of 16 other girders tested by the authors to develop structural design guidelines and guidelines on the installation and inspection of composite strengthening systems. The behaviour was also examined using value engineering to evaluate the cost-effectiveness by investigating the overall system performance. Research findings indicate that SRP materials are more structurally efficient than carbon FRP (CFRP) materials. The results of an inspection demonstration programme, including the pull-off testing of over 150 CFRP samples, has shown that the most effective inspection techniques are visual inspection, pull-off testing, and acoustic sounding.

[1]  S. Rizkalla,et al.  Bond Mechanism of NSM FRP Bars for Flexural Strengthening of Concrete Structures , 2004 .

[2]  Rosemarie Helmerich,et al.  Toolbox with Nondestructive Testing Methods for Condition Assessment of Railway Bridges , 2006 .

[3]  Amir Mirmiran,et al.  BONDED REPAIR AND RETROFIT OF CONCRETE STRUCTURES USING FRP COMPOSITES: RECOMMENDED CONSTRUCTION SPECIFICATIONS AND PROCESS CONTROL MANUAL , 2004 .

[4]  Jin-Guang Teng,et al.  Plate end debonding in FRP-plated RC beams-II: Strength model , 2007 .

[5]  Luc Taerwe,et al.  Structural behaviour and design of concrete members strengthened with externally bonded FRP reinforcement , 2001 .

[6]  A. Prota,et al.  Performance of Shallow Reinforced Concrete Beams with Externally Bonded Steel-Reinforced Polymer , 2006 .

[7]  Stephanie L. Walkup,et al.  Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-02) , 2005 .

[9]  G O Shanafelt,et al.  Damage evaluation and repair methods for prestressed concrete bridge members , 1980 .

[10]  Sami H. Rizkalla,et al.  Behavior of Prestressed Concrete Strengthened with Various CFRP Systems Subjected to Fatigue Loading , 2006 .

[11]  T J Wipf,et al.  Field/Laboratory Testing of Damaged Prestressed Concrete Girder Bridges , 1999 .

[12]  Sami H. Rizkalla,et al.  Modeling of IC Debonding of FRP-Strengthened Concrete Flexural Members , 2008 .

[13]  S. Rizkalla,et al.  Flexural behavior of aged prestressed concrete girders strengthened with various FRP systems , 2007 .

[14]  K. Harries,et al.  Deterioration of FRP-to-Concrete Bond under Failure Loading , 2006 .

[15]  A. Fam,et al.  Flexural Strengthening of RC Beams Using Steel Reinforced Polymer (SRP) Composites , 2005, SP-230: 7th International Symposium on Fiber-Reinforced (FRP) Polymer Reinforcement for Concrete Structures.