Evaluation of Repair Techniques for Impact-Damaged Prestressed Beams

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CAIT project no.: CAIT-UTC-035

Fiscal Year: 2013/2014

Status: Final

Principal investigator(s): Carin L. Roberts-Wollmann

Performing organization(s): Virginia Center for Transportation Innovation and Research

Coauthor(s): Michael Gangi, Mark Jones, Justin Liesen, Jiaxing Zhou (Research Assistants, Virginia Tech); Vanessa Pino (Research Assistant, University of Miami); Thomas E. Cousins, Ph.D., P.E. (Professor, Clemson University); C.L. Roberts-Wollmann, Ph.D., P.E., (Professor, Virginia Tech); Ioannis Koutromanos, Ph.D., (Asst. Professor, Virginia Tech); Antonio Nanni, Ph.D. (Professor, University of Miami)

Managing organization: Rutgers Center for Advanced Infrastructure and Transportation

In cooperation with: Virginia Transportation Research Council
Partner project manager: Michael C. Brown, Ph.D., P.E.

In cooperation with: University of Miami, Clemson University
Partner project manager: N/A

Supported by: Virginia Department of Transportation

Supported by: Federal Highway Administration

Supported by: U.S. Department of Transportation/OST-Office of the Assistant Secretary for Research and Technology

UTC, grant, or agreement no.: DTRT12-G-UTC16


Collisions between over height vehicles and bridges occur about 1,000 times per year in the United States. Collision damage to bridges can range from minor to catastrophic, potentially requiring repair or replacement of a bridge beam. For prestressed concrete beams, the traditional repair methods are strand splices and Fiber-Reinforced Polymer (FRP) wraps. A new material, Fabric-Reinforced Cementitious Matrix (FRCM), has been developed as an alternative to traditional FRP wrap.

The first objective of this project was to damage, repair and test four beams retrieved during the demolition of the overpass of Arcadia Road over Interstate 81 at Arcadia, VA. The repair techniques evaluated were strand splices, FRP, FRCM and a combination of FRCM and strand splices. The beams were tested in the lab in simple span configuration with the repair location placed in a region of constant moment. Loads were applied monotonically to failure. One beam was tested in an undamaged condition as a control.

Several methods were used to calculate strength and behavior. Simple methods from AASHTO and ACI were used for hand calculations of flexural strength. Conventional strain compatibility was also used. Non-linear beam models and non-linear three dimensional finite element models were also investigated as tools to evaluate repaired beams. Material characterization was performed on the concrete, prestressing steel, splice chucks, FRP and FRCM. The material characterization was used to develop the material models for the analyses.

It was found that the greatest percentage of original strength was returned by the FRP repair and the repair with the combination of FRCM and splice chucks. The lowest percent was returned with only splice chucks when eight of 48 strands were severed and spliced. The FRCM proved to be a viable repair technique, but should be tested in fatigue before deployment on a bridge with high truck traffic. The analysis methods were shown to provide good estimates of strength and load-deflection behavior.