---
title: Case Study - Spillway Void Fill Stabilizes Slabs and Stops Water Damage
description: Discover how AP Lift 440 high-expansion foam stabilized spillway slabs, halted water intrusion, and saved 65% vs. traditional methods.
---

[Alchatek Infrastructure Repair Blog: Polyurethane Leak Seal Injection, Soil Stabilization, Concrete Leveling ](https://info.alchatek.com/blog)

# [Case Study - Spillway Void Fill Stabilizes Slabs and Stops Water Damage](https://info.alchatek.com/blog/case-study-spillway-void-fill-stabilizes-slabs-and-stops-water-damage)

 Written by [Landon Feese](https://info.alchatek.com/blog/author/landon-feese) | May 6, 2026 2:00:02 PM

Water infiltrated beneath spillway slabs at a campground, eroding soil and creating voids that cracked concrete. Leaks surfaced through cracks, threatening structural integrity. [SiteMix Pressure Grouting, LLC](https://sitemix.us/) was called in to repair the damage.

## Initial Assessment

Probing revealed extensive voids beneath spillway slabs where water removed supporting soil and destabilized the structure. Traditional tear-out and replacement demanded extended closure, heavy equipment access, and prohibitive costs for this operational facility.

## Proposed Solution

[AP Lift 440](https://alchatek.com/geotech/polyurethane-concrete-leveling-products/slab-foundation-lifting-ap-lift-440/) proved the perfect solution, featuring an 18x expansion ratio, 11,520 psf compressive strength for slab stabilization, and hydrophobic properties to prevent water infiltration.

## Procedures

1. Established 4-foot grid pattern at lowest spillway area.
2. Drilled injection points through slabs.
3. Injected AP Lift 440 systematically across grid.
4. Monitored foam spread between injection points.
5. Completed both spillway sides plus access ramps.

## Results

Completed repair in two days with zero downtime.  
Stabilized slabs and eliminated all water intrusion with visible concrete drying confirming effectiveness.  
Achieved approximately 65% cost savings compared to traditional concrete replacement while avoiding weeks of disruptive demolition.

### Want more information on polyurethane geotech products?

[View full post](https://info.alchatek.com/blog/case-study-spillway-void-fill-stabilizes-slabs-and-stops-water-damage)

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