Engineering Stability: Subgrade Void Stabilization and Precision Concrete Lifting in Waverly, IA
Challenge
A residential property in Waverly, Iowa presented critical failure points along its concrete driveway matrix. Heavy dynamic loading from seasonal maintenance equipment, combined with subgrade soil erosion, caused significant differential settlement. Individual slabs had dropped out of alignment, creating severe trip hazards and mechanical catch points. System Design Specialist Daniel Kelchen performed a thorough site assessment, diagnosing subgrade voiding caused by localized moisture infiltration and subsequent soil consolidation.
Traditional removal and replacement was ruled out; adding high-mass new concrete over unstable, uncompacted subgrade would trigger future failure. Daniel engineered a non-destructive remediation plan utilizing high-density, structural-grade polyurethane injection to consolidate the subgrade and restore structural equilibrium.
Solution
Foreman Ricky Sigala and crew member Jaylen executed the technical layout and deployment:
Subgrade Consolidation & Lifting: The crew drilled a strategic grid of micro-injection ports (5/8-inch diameter) through the settled slabs. Jaylen utilized specialized, dual-component equipment to inject the PolyLevel® system directly beneath the concrete.
Chemical Reaction & Hydrophobic Properties: Upon leaving the mixing nozzle, the two-part liquid polymer initiated an exothermic reaction, expanding rapidly to fill the underlying voids. Working downward first, the material consolidated the loose subgrade soils. Once contained, it generated an upward lifting force of up to 6,000 lbs per square foot. Because PolyLevel is completely hydrophobic, it displaced localized moisture and created a permanent, waterproof barrier immune to future soil washouts.
Precision Alignment: Ricky monitored the slab elevations in real-time, leveraging the rapid gel and rise time of the polymer to achieve exact, flush alignment with adjacent slabs. This lightweight formulation adds only about 2 lbs per cubic foot, ensuring no unnecessary stress was placed on the load-bearing strata.
Monolithic Joint Sealing: To permanently eliminate the root cause of the initial soil erosion, the crew purged all open joints and structural cracks of debris. They filled these vectors using NexusPro® Joint Sealant. This medical-grade silicone sealant maintains elastomeric flexibility across extreme Midwestern thermal cycles, preventing surface water runoff from penetrating the subgrade.
