100-Year Design Service Life of CPL Lined Concrete Systems
These are the top 8 considerations when designing and implementing a lined concrete system using CPL. They are designed to target a 100-year Design Service Life - including wastewater treatment plants (WWT'P’s), trunk lines, manholes and maintenance holes, etc.
Ensure the Use of a High-Quality Concrete Protective Liner (CPL)
For long-lasting concrete protective liners (CPL), selecting experienced and vetted material manufacturers is crucial. Ensure that the product has passed all necessary testing by a third party, uses a high quality base resin and is manufactured in a one-step process. For large diameter projects, having wide sheet width options is also extremely valuable. There are only a few manufacturers on a global scale that provide this high level of quality.
Does the Manufacturer Offer Adequate Accessories Besides CPL Roll Stock?
Accessories are the unsung heroes of a system designed with a 100 year design service life. Systems should use a product line that has access to T-profiles, End-profiles, conductive sheet, fabric backed sheet, etc, to provide a holistic containment system - no matter the shape or size. This is most important for cast-in-place jobs.
Precast Design, Production, Handling, and QA/QC Procedures
The precast phase is crucial for the longevity of CPL lined systems like manholes and pipes. High-quality production, accurate sizing, and proper welding are essential to prevent future problems. Precision in cutting and aligning CPL panels is critical to ensure a proper fit and avoid issues like leaks or structural weaknesses. Missteps in precast production can lead to significant repair costs and reduce the system's overall quality. Proper techniques and attention to detail in this early stage are paramount for long-term durability. Engineered Containment works as a partner with our precast clients to ensure this step is executed with excellence.
Cast-In-Place Formwork Design, Cladding, Gapping, and Accessory Utilization
Formwork, whether wood or steel must be clad with CPL while accommodating for expansion and contraction. This requires unique fastening to prevent wrinkles. The use of specific accessories improves alignment and seals the CPL, reducing concrete leakage and enhancing quality. Proper use of these accessories simplifies welding and ensures correct gaps, preventing costly misalignment’s and repairs. Accessories like corner pieces ensure better weld quality compared to traditional methods. Proper patching is also essential for maintaining structural integrity. At Engineered Containment we firmly believe that it is best to leave CPL installation to the experts. Some of the biggest CPL related problems we have been called in to fix were related to contractors taking on this scope without an expertise in the field because they thought it looked simple.
5. In-Plant and In-Situ Extrusion Welding Quantity
Reducing weld joints can decrease failure risks but must balance against weld quality and the need for material flexibility to prevent issues like wrinkles or gaps. Using more welds in specific areas, like replacing complex welds with simpler flat ones pays off in long-term durability, aiding in achieving a century-long service life. Failure to adopt this can undermine the system’s longevity.
6. In-Plant and In-Situ Extrusion Welding Quality
Extrusion welding’s success depends heavily on the technician's skill and experience, as they control the weld's speed and consistency. Proper training and certification, particularly by recognized bodies like the International Association of Geosynthetics Installers (IAGI), are crucial for ensuring the longevity and quality of the welds. At the very minimum, be sure that whoever welds the CPL has a manufacturer’s certification. Pre-weld testing under expected conditions ensures readiness and suitability for the project's specific requirements.
7. QA/QC Techniques
Quality assurance and quality control (QA/QC) in CPL applications heavily rely on using the right accessories, skilled technicians, and adherence to ASTM standards. Routine checks like qualification welds and spark or vacuum tests are vital. Misusing testing methods can lead to incorrect results, compromising the project's integrity and lifespan. If you have questions about specific QA/QC tests and methods, please reach out. We would be happy to discuss.
8. On-Going Surveillance, Inspections, Maintenance, and Repairs
Regular inspections and maintenance are crucial for CPL systems, similar to how vehicles require checks to prevent severe damage. CPL damages, like minor breaches or weld failures, can be fixed cost-effectively if caught early. Inspections should occur every two to five years, depending on potential damage risks, and can be done via CCTV or directly, ensuring the system's longevity and preventing extensive damage.
Are you in the process of designing or refurbishing infrastructure and are wondering if CPL is the right fit? We’re happy to help. Engineered Containment is not only a contractor dedicated to executing these systems, we are also an engineering firm with our permit to practice in multiple jurisdictions.
