Bond Quality of Fiber Reinforced Polymer (FRP) Concrete Strengthening Systems

Project ID: 3780
Principal Investigator: Kurt Von Fay
Research Topic: Repair and Maintenance
Funded Fiscal Years: 2005 and 2006
Keywords: None

Research Question

* Can FRP technologies be useful to Reclamation?

A major advancement in the field of concrete technology is the use of FRP to strengthen concrete structures. Very basically, synthetic fiber sheets are impregnated with a polymer and attached (glued) to concrete elements. The technology is rapidly gaining use in strengthening columns, pipelines, walls, and floors. Strengthening may be required due to new earthquake loading information, blast resistance, or improving strength of deteriorated concrete structures.

A key component to the success of these systems is the quality of the bond between the concrete and the FRP. Currently, there is no standard method to measure that bond. Several methods have been attempted, but there is wide variability in measurements and there is no consensus on which method(s) should be used.

Need and Benefit

Strengthening structures may be needed for a variety of reasons, including new earthquake loading information, blast resistance, or improving strength of deteriorated concrete structures.

Currently, when we need to strengthen a structure, we either add concrete, add steel, or rebuild the structure. When problems were discovered with the siphons for the Central Arizona Project (CAP), the siphons were either rebuilt or lined with additional steel. Both solutions were very expensive. When problems with shear capacity of the spillway walls at Pineview Dam were found, the solution was to anchor steel plates on the spillway wall using cutom made anchors. Again, this was an expensive solution to adding shear resistance.

A major advancement in the field of concrete technology is the use of FRP to strengthen concrete structures. Very basically, synthetic fiber sheets are impregnated with a polymer and attached (glued) to concrete elements. The technology is rapidly gaining use in strengthening columns, pipelines, walls, and floors. The fibers that comprise the sheets can be synthetic polymers, glass fibers, or steel.

FRPs offer an attractive alternative to our current practices for strengthening structures. Since this is new technology, there are a number of issues surrounding its use. A key component to the success of these systems is the quality of the bond between the concrete and the FRP. Currently, there is no standard method to measure that bond. Several methods have been attempted, but there is wide variability in measurements and there is no consensus on which method(s) should be used.

This research will examine factors that impact bond strength. It will also give Reclamation a chance to learn more about the technology and possible uses.

After studying these factors, we will make recommendations on appropriate methods to measure bond strength.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Bond Quality of Fiber Reinforced Polymer Concrete Strengthening Systems (final, PDF, 25.6MB)
By David Godaire, Kurt VonFay, Timothy Gumina
Report completed on October 14, 2011

Fiber reinforced polymer (FRP) sheets were attached to the top face of concrete slabs. The top surfaces of the slabs were prepared using four different surface preparation methods. The methods were: surface grinding, sand blasting, bush hammering, and power washing. Bond strength of the FRP bonded to the concrete surface was measured using two different pull off adhesion testers; the Elcometer 106 device and the PosiTest® Pull-Off Adhesion Tester.

Return to Research Projects

Last Updated: 6/22/20