Project: Katoen Natie (KTN)
Location: Houston, TX
Asset: Hundreds of thousands of SF of industrial concrete pavement at a 24/7 distribution facility near the Port of Houston
CHALLENGE
Katoen Natie is an industrial complex near the Port of Houston with multiple locations. Its distribution facility runs 24 hours a day, 7 days a week, with a high flow of heavy truck traffic over hundreds of thousands of square feet of concrete pavement. Built near the Port, the site has a high water table and poor soil conditions, and the subgrade was not adequately stabilized for the designed use when the pavement was installed. Continuous heavy 18-wheeler traffic was driving groundwater to the surface and pumping it through the expansion joints, washing out the subgrade and leaving voids. That in turn caused slab deflection, settlement, and eventual failure. Operational downtime was a significant factor as well.
SOLUTION
Superior was selected to lift, re-level, and re-support the settled slabs back toward their original position using the PolyLift polyurethane injection process. Small 5/8-inch holes were drilled on a grid pattern across the affected areas, and a two-part urethane was injected through these ports. The chemical reaction converts the liquid components into a strong, rapidly setting rigid foam. In its foam state the polyurethane is relatively light, weighing two to six pounds per cubic foot (pcf), whereas other void-filling or slab-lifting materials can weigh upwards of 130 pcf, adding significant weight to already weak soils and potentially worsening settlement. With a compressive strength of 100 pounds per square inch (psi), the polyurethane provides the resistance needed to support heavy loads. Areas were sectioned off and repaired independently to keep traffic moving, and because of PolyLift's quick-set nature, each area was reopened to traffic just 20 minutes after injection.
RESULTS
Superior has repaired tens of thousands of square feet of concrete pavement across the KTN facilities.
Product installed: PL 400 High-Density Polyurethane (approximately 6 pcf typical in-place density, 100 psi compressive strength).
The lightweight, high-strength foam filled the voids and stabilized the slabs without adding significant load to the weak subgrade, and repaired areas returned to heavy truck traffic within 20 minutes.
