Executives at a prominent shipbuilding company discovered a significant problem at one of their largest shipyards. Soil was migrating from the landward side of the bulkheads into the water, resulting in erosion and compromising the stability of the dock slabs. The shipbuilding company enlisted Helms PolyFoam, a local specialist in soil stabilization and concrete repair, to address the issue. Helms PolyFoam collaborated with Alchatek to develop a comprehensive repair plan. Their strategy focused on two key solutions: joint sealing and slab stabilization, designed to reinforce the bulkheads and fill voids beneath the concrete slabs.

Powerful Polymers

For soil erosion prevention and stabilization, the contractor selected AP Fill 720, a highly expansive geotechnical polyurethane foam known for its effectiveness in sealing leaks and reinforcing loose soil. To address the large voids beneath the slabs and ensure their stability, they opted for AP Lift 475, a high-density geotechnical polyurethane foam designed for concrete leveling, void filling, and soil stabilization.

Painless Procedures

To combat soil loss, AP Fill 720 was injected at 24-inch intervals along the wall. This spacing allowed the material to flow and connect between injection points, forming a grout wall that stabilized the loose soil. The process created a water-impermeable barrier, securing existing soil and mitigating loose soil along an 8-10 foot test section of the wall. At each point, a 1/2-inch steel tube was inserted to a depth of approximately 30 feet.

For slab stabilization and void filling, AP Lift 475 was injected beneath the concrete in a zigzag pattern. Using 3/8-inch holes and 1/2-inch steel tubes, the resin was introduced into the soil. As it expanded, it compressed the soil, filled voids, and generated positive pressure on the slab.

Rapid Results

The joint sealing and slab stabilization methods yielded excellent results. They effectively reinforced the wall, stopped soil erosion, and halted void formation. The structural polyurethane resins used proved to be a durable and efficient fix.

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