The Wyoming Department of Transportation reports that motorists who utilize the North Sheridan Interchange Bridge may notice a slight dip on either end of the bridge approach.
According to WYDOT, this slight drop is a result of the subgrade soils settling. But rather than remove the concrete approach slab, WYDOT will utilize a unique lifting process using a material called High Density Polyurethane Foam. This foam is injected into the existing concrete slab and brings the existing concrete slab to grade, eliminating the drop.
WYDOT is scheduled to utilize this technique on the North Sheridan Interchange Bridge approaches the week of April 18.
The contracted team will drill a series of 5/8” holes the full depth of the concrete pad in a grid pattern. The team will then inject those holes with the polyurethane which travels throughout the voids and expands up to 25 times. This polyurethane is a high-density, structural polyurethane that increases the soil’s weight bearing capacity and stabilizes the sub-grade. Once the soil is stabilized, additional polyurethane is injected to provide lift and realigns the slabs and overlying pavement bringing them up to grade. This process provides proper support to the soil and heavy sleeper slabs to mitigate against future bridge settlement.
An example of what the polyurethane looks like under the concrete slab. Photos courtesy of Concrete Stabilization Technologies.
The process is expected to take one week. WYDOT contractors will perform these repairs in four sequences. During this time there will be lane closures to allow for the repairs. Traffic control, including signage and flaggers will be in place directing traffic around the repairs.
Last modified: April 14, 2022