Pavement Rehabilitation of the New York State Thruway MP 438.5 to MP 451.5 in Erie County, NY
This project was divided into four five mile phases, two phases being constructed during one construction season. The project specified that the pavement type for one of the four phases be constructed as an unbonded concrete overlay for a test section. This section is the first time that an unbonded concrete overlay was designed and installed on the 400 mile plus thruway.
Several challenges were overcome both in design and in construction. The existing roadway was originally installed during the initial construction of the thruway during the 1950’s. Old highway design did not account for changes in cross slope in horizontal curves. New FHWA guidelines require that the cross slopes change on horizontal curves. The challenge during design was how to marry the old design to the new design. The designers choose to make up the cross slope mismatch with the asphalt inner layer. Typically on unbonded overlays, the inner layer is a consistent thickness (typically 1 to 2 inches). Due to the conflict in cross slopes, the inner layer varied from 1.5 inches up to 9 inches. This inconsistency poised a construction challenge with regard to the anchoring of the transverse joint support assemblies. The old concrete pavement prevented using the typical anchor stakes. If the asphalt inner layer were consistent, gun powdered charges could have been used to set anchor nails into the old concrete.
Given these challenges, Surianello opted to install all of the transverse dowels in the overlay section utilizing a mechanical dowel bar inserter. This was a first for Surianello. GOMACO Corporation provided the equipment and field expertise to make this happen perfectly.
Another challenge was access to the project for the delivery of material (concrete). Typically, haul roads are constructed outside the limits of the guide wire that is used to guide the slip form paving trains. These haul roads need to be substantial enough to stand up to thousands of truck loads yet easily removed so that the original ground contours could be restored. Given the compressed schedule, Surianello investigated and implemented stringless technologies to guide the slip form paver and IDBI. Again, another first for Surianello. Surianello accomplished this project with two firsts and the end result was a pavement that exceeds specifications both in smoothness and quality.