Four delaminated bridges were epoxy injected and compared to noninjected bridges so that information on delamination repair durability, frequency, and costs could be collected. The injection history, cores, and condition reports for each bridge demonstrated that the plane of delamination once repaired, stayed repaired, but a new delamination may form above, below or adjacent to the one repaired, yet the deck surface remained intact even when the frequency of repair was once every three or four years.

The primary objective of this project is to identify several common bridge deck maintenance activities that are performed by contract, review the current Arizona Department of Transportation (ADOT) specifications for those maintenance activities, modify the specifications where appropriate to reflect current accepted practice, and serve as a model to guide future efforts at updating specifications. To complete the project, all of ADOT's bridge deck maintenance specifications were reviewed. The following repairs were identified for further evaluation: (1) Temporary repair of expansion joints; (2) Minor collision damage repair of concrete I-beam girders; (3) Hole in deck repair (with and without asphalt overlay); and (4) Bridge railing repair (concrete and aluminum). Bridge preservation specifications from other agencies were then collected and reviewed. This led to the selection of two treatments to develop new draft specifications: (1) Bridge Deck Repair: Full-Depth Patch; and (2) Prestressed Concrete I-Beam: Minor Repair by Patching and Epoxy Resin Base Adhesive Injection. Draft specifications were developed and submitted to ADOT for review and possible implementation, thereby completing the project.

The Iowa demonstration project to promote the rehabilitation of bridge deck concrete by rebonding delaminations with injected epoxy is a 150 ft x 150 ft high truss bridge on Iowa route No. 210 over Indian Creek near Maxwell in Story County (Service level D, AADT-730, Inventory Rating HS-16.9, Operating Rating HS-25). The objective of this study was to evaluate the effectiveness of repairing a delaminated bridge deck by epoxy injection, specifically a bridge deck with a delaminated portland cement concrete overlay.

One strategy to regain structural integrity of cracked reinforced concrete bridge deck girders is to inject the cracks with epoxy. Many bridge owners allow all traffic to use the bridge during injection and curing, while other bridge owners restrict traffic to produce a hold time in which cracks do not open and close. This research study used a laboratory set up to determine the effect of temperature and hold time on epoxy undergoing curing. The comparative measure was the tensile strength of the epoxy after curing. The results showed that traffic should be restricted to stop the crack motion during injection and until the epoxy sets. After the epoxy has set, crack motion while the epoxy undergoes full cure degrades the tensile strength of the epoxy, but not to levels that would affect the structural integrity of the beam.