48-INCH CULVERT REHABILITATION USING STEAM-CURED CIPP

Savy & Sons was engaged to rehabilitate a deteriorating 48-inch corrugated metal pipe (CMP) culvert located beneath a roadway in a Connecticut municipality. The culvert served as a critical stormwater crossing, carrying overflow from a natural pond and wetland area to a downstream stream.

Due to the condition of the existing pipe and the logistical constraints of the site, the client required a solution that would restore the culvert without excavation, road closure, or disruption to emergency access. Savy & Sons implemented a trenchless cured-in-place pipe (CIPP) lining solution utilizing steam curing to efficiently rehabilitate the structure and restore long-term performance.

PROBLEM

The existing 48-inch CMP culvert had reached the end of its service life. The pipe showed significant deterioration, including corrosion, voids, and loss of structural integrity along the invert.

Compounding the issue, the culvert was located beneath a dead-end roadway that required continuous access for emergency services. Traditional dig-and-replace methods would have required full roadway excavation, extended closures, and complex coordination with surrounding utilities.

Additional site challenges included:

• • • • Active water flow from an upstream pond and wetland area
      • The need to maintain access for fire, police, and municipal vehicles
      • Existing underground utilities, including a gravity sewer and force main, limiting excavation options

The client needed a solution that could restore the culvert quickly, safely, and without disrupting roadway access.

SOLUTION

Savy & Sons implemented a steam-cured CIPP lining solution to rehabilitate the existing culvert in place. This trenchless approach allowed for the installation of a new structural liner within the existing pipe, eliminating the need for excavation.

Key elements of the solution included:

Trenchless CIPP Installation
A resin-impregnated liner was inserted into the existing 48-inch pipe and inflated to conform to the host pipe, creating a new continuous structural pipe within the existing culvert.

Steam Curing Process
High-temperature steam was introduced to cure the liner in place, significantly reducing cure time and enabling same-day return to service. Steam curing provided a controlled and efficient method for achieving proper liner strength and long-term performance.

Water Control & Bypass
To maintain a dry and controlled work environment, the upstream pond was temporarily dammed and water was bypassed around the work area, preventing flooding during installation.

PROJECT EXECUTION

The project was completed over a two-day period with a focus on efficiency and minimal disruption.

On the first day, the pipe was prepared and staged for installation, including pulling in glide foil and positioning all necessary equipment. This preparation ensured a smooth and efficient installation process.

On the second day, the liner was installed and steam cured on-site. The entire rehabilitation—from installation to curing—was completed within a single working day, allowing the pipe to be returned to service immediately following completion.

RESULTS

The culvert rehabilitation project was completed successfully, delivering a long-term solution with minimal impact to the surrounding area.

Key outcomes included:

• • • • Full structural rehabilitation of the 48-inch culvert without excavation
      • Completion of installation and curing within a single day
      • Elimination of the need for road closure or extended service disruption
      • Maintenance of continuous access for emergency services
      • Installation of a new pipe with an expected service life of 50+ years
      • Accelerated Project Timeline: Steam curing allowed the liner to be installed and returned to service in a single day, avoiding the extended downtime associated with traditional replacement methods

CONCLUSION

This project highlights the effectiveness of steam-cured CIPP lining as a fast and efficient solution for rehabilitating large-diameter culverts in access-constrained environments. By eliminating the need for excavation and significantly reducing installation time, Savy & Sons was able to restore critical infrastructure while maintaining roadway access and minimizing disruption.

The use of steam curing enabled rapid turnaround and reliable performance, making it an ideal solution for projects where time, access, and site conditions are critical factors.