State Highway Box Culvert Repair in Kentucky


On KY 583, east of Elizabethtown, Kentucky, water was travelling beneath the floor slab of a box culvert, and the roadway approach and departure above were beginning to settle. Officials with the Kentucky Transportation Cabinet called URETEK.


URETEK arrived on location and inspected the box culvert. Dynamic Cone Penetrometer (DCP) testing confirmed the presence of voids beneath the floor slab. Over time, fines in the base soils had been carried away with the water flow, leaving the identified voids. As the problem became more pronounced over time, the roadway above had begun to settle. Based on the DCP test results, an injection plan was developed for the site, and URETEK Deep Injection® (UDI) was proposed to fill the voids, stabilize the base soils, and lift the roadway above the box culvert back to its design grade.


As part of the site-specific injection plan, UDI was conducted beneath the roadway pavement as well as underneath the box floor slab. URETEK’s 486 Star® polymer was the ideal material for the job, with its ability to set up underwater proven on this project. Initial injections beneath the box culvert filled the voids and blocked future erosion. Above the culvert, UDI conducted from the roadway delivered polymer to various depths down to 12 feet beneath the roadway.


Following UDI, the roadway pavement system was lifted back to its original elevation and the box culvert below was sealed so that no water could travel beneath it, halting future erosion and void space formation. During the project, no traffic control was needed, as one lane remained open while the work was performed. KYTC officials were thrilled with the results, and normal traffic resumed on KY 583 immediately upon completion of the job.

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.

Square with flowing water underneath


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