The Gurley Overpass Deck Rehabilitation Project will address delamination of the existing deck and will facilitate the placement of a durable epoxy overlay with a high friction surface.

The work involved will require full time oversight with some specialty inspection unique to this type of work. Initially, the deck will be milled.  This process should remove most of the delamination identified in the preconstruction reconnaissance of the deck.  The deck will then be evaluated by the engineer for remaining areas of delamination.  This will be done by sounding, or "chaining" the deck.  The unsound concrete in areas where delamination is detected will be marked for hand removal.  The removal process will be observed to control the extent and adequacy of the removal.

Once the unsound concrete has been removed, a shrinkage controlled silica fume overlay will be placed.  This process will be performed at night and will require close environmental monitoring to ensure the humidity, air temperature, and wind conditions are within  specifications. 

The silica fume concrete requires a 5 to 7 day wet cure. During this time period the deck will be covered with burlap and plastic to facilitate the wet cure process.  The deck will then need an additional three (3) weeks to fully hydrate and reach design strengths.  During this period, traffic may be allowed on the overpass. After the curing period is complete, a subsequent closure will be required to prepare and place the epoxy overlay.

The bridge deck work will be performed according to Wyoming Department of Transportation Specifications.

To make the most of the overpass closure and to minimize future traffic disruption, broken and worn concrete paving in the intersection of 4th Street and Gurley Avenue will be replaced. 

Included in Structural Dynamics' scope of work is specialty inspection of the deck, daily construction observation, materials testing (by a subcontractor), and project closing per the City of Gillette Standard Construction Specifications.

The funding for this project has been allocated through the 1% Optional Sales Tax Account 201-10-05-419-70-47404, Bridges Fund, for $1.1 million.

S&S Builders was awarded the project on April 3, 2018 in the amount of $913,121.20.  Powder River Construction was the only other bidder on this project for $915,528.25, less than a ¼ percent spread in bids.

Structural Dynamics' proposed construction administration cost is $129,873.68 (approximately 14% of the construction bid).  When compared to the City's history of average daily fees associated with similar City projects, this proposed Professional Services Agreement contract amount is within reason with consideration of the specialty inspection that is required.