History

The Gurley Overpass was constructed in 1982 to span Highway 14-16 and the Burlington Northern mainline.  In 1999, the center expansion device was replaced and the deck resurfaced.  In 2010, the expansion device was again replaced, the support bearings on the north half of the span were replaced, the north abutment was tied back and stabilized, and the deck was repaired by removing delaminated concrete and resurfaced with a silica fume overlay.  In 2013, cracking in the deck was sealed with a healer sealer product to reduce water penetration.  In 2015, water damage to the north abutment and Pier #5 beneath the expansion device were repaired.  In 2017, the barriers were evaluated and resurfaced to extend the barriers useful life.

This Scope of Work

This scope of work is similar to the 1999 and 2010 deck repairs with the addition of a high friction epoxy overlay.  The unsound concrete in the delaminated areas of the deck will be removed and the deck prepared for a new silica fume overlay.  After the overlay is adequately cured, the overlay will be prepared to receive an epoxy overlay.  The epoxy overlay involves two layers of epoxy with high friction aggregate.  The epoxy overlay will seal the deck from water and contaminate intrusion, adds to the strength of the deck, and provides a high friction wearing surface.

Additionally, while the overpass is closed for the deck repairs, broken and worn concrete paving in the intersection of Gurley Avenue and 4th Street at the south end of the overpass will be replaced.

Anticipated Schedule and Overpass Closure

The contract allows for 60 working days to substantial completion.  We anticipate that the overpass will be closed continuously for approximately 10 weeks, be reopened for 3 to 4 weeks while the silica fume hydrates, then closed again for another 2 weeks to complete the epoxy overlay.  This schedule is an estimate of how the days within the contract will be allocated and we anticipate this estimate to change once the successful contractor refines the schedule.

The contract allows for, but does not require, extended working hours and Saturday work.

Two (2) bids were received and read aloud by the City of Gillette Purchasing Division at 3:00 PM on March 20, 2018.  The Bids were as follows:

The two bids were within $2,407, or 1/4%, of each other.  The low bid was 12% greater than the engineer's estimate.  Much of that difference was in the silica fume overlay bid item.

The engineer's estimate was based on comparable pricing from WyDOT bid tabulations.  Recent changes to the WyDOT specifications for shrinkage reducing additives is the apparent reason for the increase in silica fume cost.

No errors or irregularities were discovered in the bid packages.  S&S Builders has been contacted and they are satisfied with their bid.  S&S Builders has significant experience with this type of work.

The budget for this work is $1,100,00.00.  Final design and bidding was $24,186.00.  $162,692.80 remains for Construction Administration and any unforeseen changes to the scope of work.

Funding for this project has been allocated from the 1% Optional Sales Tax Account 201-10-05-419-70-47402.