Void Fill After Bursting Pipe in Ontario

The Challenge

Burst pipe created voids underneath a concrete floor.

A bursting pipe can have devastating consequences for soil, and for this commercial facility, the story is no different. Underneath the slab on grade floor, a pipe failed, washing away support soils and leaving empty pockets called voids. Without support soils, the concrete slab above is at risk for settlement, cracking, and worst of all: total failure. These voids existed under multiple areas of the concrete floor, spread across the entire building. The 8 voids were a detriment to the building, requiring their filling and stabilization of the above concrete slab on grade floor. Left unaddressed, the structural integrity of the facility and the safety of those inside would have been compromised.

Key Facts

The Solution

Working as a team to identify voids and fill them with polyurethane.

Groundworks collaborated with a company called First OnSite to remediate the conditions under the floor. As a team, they investigated the soil conditions using Ground Penetrating Radar (GPR) to detect the voids beneath the floor and mark them on a map. After this crucial step, technicians from Groundworks drilled small, penny sized holes in the concrete through which they injected an expansive two component polyurethane. This polyurethane, known for its exceptional expansion capabilities, filling in the empty soil pockets left by the pipe failure. As the polymer expanded, it sealed off the voids and rebuilt continuous soil-to-slab contact, locking the floor into a stable condition before settlement could occur.

The Impact

Voids filled and floor stabilized.

The polyurethane not only filled the voids in the soil, but reestablished soil contact to the slab, stabilizing the floor and preventing potential failure. By restoring the subgrade support, the repair eliminated the risk of uneven settlement that could have led to cracking or hazardous conditions. This void filling job was completed quickly, allowing immediate use of the floors and for the Groundworks team to continue working on other work that would also remediate the floors. The rapid turnaround minimized downtime for the property owner, reducing disruption to operations while ensuring the integrity of the slab for long-term performance.