The Challenge
- Fill the annular space between an existing 18-inch concrete storm pipe and new 13-inch liner pipe
- Address approximately 40 feet of pipe
- Support the deteriorating existing pipe around the new liner
- Protect the liner from potential damage if the existing pipe continued to deteriorate
- Eliminate the annular space as a potential pathway for unwanted water movement
- Complete the work quickly with minimal disruption to the surrounding construction project
The Solution
RaiseRite used FillFoam™ as an annular grout to fill the space between the existing concrete pipe and the new storm drain liner.
Because the pipe run was approximately 40 feet long, a placement hose was extended through the annular space to the far end of the pipe. FillFoam was produced onsite and pumped through the hose. As the annular space filled, the hose was gradually extracted, allowing the material to be placed progressively along the length of the pipe.
After placement was completed, the accessible end of the annular space was capped with a spray-applied dual-component polyurethane foam bulkhead.
This approach allowed the irregular void between the two pipes to be filled without removing the deteriorated concrete pipe or requiring extensive additional excavation.
The Summary
- Approximately 40 feet of annular space successfully grouted
- Existing 18-inch deteriorating concrete pipe left in place
- New 13-inch liner surrounded and supported within the existing pipe
- Annular void filled to help prevent unintended water pathways
- No extensive excavation or removal of the existing concrete pipe required
- FillFoam™ produced onsite for an efficient installation
- General contractor able to continue with the facility expansion project
Value Delivered:
This project demonstrates how FillFoam can provide an efficient solution for annular grouting when a new pipe is installed inside deteriorating existing infrastructure. By extending a placement hose through the pipe and progressively withdrawing it during installation, RaiseRite was able to fill the annular space along the approximately 40-foot run. The lightweight FillFoam was produced onsite and placed without removing the existing storm pipe, providing a quick, minimally invasive solution that supported the pipe system, protected the new liner, controlled the open void space, and allowed the larger construction project to move forward.
