Asphalt Pavement Preservation for NM DOT
Problem
On Highway 491 south, at milepost 27.3 just outside of Tohatchi, New Mexico, DOT District 6 engineers were looking at a pavement heaving problem that presented significant ride quality and safety issues for the traveling public. Expansive soils deep in the subgrade were at work, and officials knew that the speed at which the pavement system can change in that area makes it difficult to maintain the roadways. They called URETEK.
Analysis
A quick visit to the site and some research into previous jobs confirmed URETEK’s assumptions about the soils in the area. It was quickly determined that the URETEK Deep Injection® (UDI) process would be the ideal solution for New Mexico DOT at this location.
Solution
URETEK crews performed UDI in a grid pattern that allowed the polymer to strategically expand and stabilize the subgrade and subbase while lifting the pavement in both directions to taper out the heave and restore ride quality and safety for drivers on Highway 491.
Result
NM DOT officials were pleased with the results. The total repair time compared to other methods was dramatically reduced, as the removal and replacement of the expansive soils was not required. As such, the repair job involved virtually no environmental footprint. During the project, one lane remained open to minimize traffic disruption. Finally, the URETEK repair solution represented a tremendous dollar savings for District 6 engineers when compared to rip-and-replace methods.
URETEK Deep Injection® (UDI)
Widely referenced throughout our industry, UDI involves the injection of structural polymer into base and subgrade soils to increase the load bearing capacity. This is achieved by injecting the polymer through small holes drilled directly through the pavement structure to depths determined by site-specific analysis. Our URETEK 486 Star® material flows easily into voids and weak zones within the soil mass below. Through a controlled chemical reaction, the expanding polymer compacts surrounding soils and applies a controlled pressure on targeted areas of the affected pavement above. If needed, a multi-injection design plan is utilized to gently return the pavement to its original grade. The composite material quickly cures into a strong, dimensionally stable, and water-resistant geo-material, providing years of reliable service.
URETEK 486 Star®
URETEK 486 Star® polymer is a two-component, high-density, expanding thermoset polyurethane system. It was developed to be the ideal solution for under-sealing, void filling, lifting of settled pavement, stabilization and stiffening of weak soils, and for encapsulating and sealing buried infrastructure. URETEK 486 Star® is environmentally inert, non-toxic, and resists underground water erosion or weakening due to its industry-leading hydrophobic properties.
