Evaluation Of High Performance Concrete Overlays Placed On Route 60 Over Lynnhaven Inlet In Virginia

Sixteen high performance concrete overlays were placed on two 28-span bridges on Route 60 over Lynnhaven Inlet in Virginia Beach, Virginia, in the spring of 1996. The construction was funded with 20 percent Virginia Department of Transportation maintenance funds and 80 percent special ISTEA Section 6005 federal funds specifically allocated to demonstrate overlay technologies. ISTEA funds were also used to evaluate the installation and condition of the overlays and to prepare an interim report and this final report. The installation included a total of 16 overlays: 13 concrete mixtures that included a variety of combinations of silica fume, fly ash, slag, latex, corrosion-inhibiting admixtures, a shrinkage-reducing admixture, and fibers; an overlay with a thickness of only 0.75 in (19 mm); and spans with and without topical treatments of two corrosion inhibitors. With the exception of one of the systems, the overlays were required to have a minimum thickness of 1.25 in (32 mm). Another system had a variable thickness ranging from 1.25 to 0.75 in (32 to 19 mm) to provide good ride quality. All the overlays have performed well with the exception of most of the areas adjacent to joints. Many of these areas were replaced by the original contractor and replaced again by the city of Virginia Beach.