Abstract

The use of carbon fiber-reinforced polymer (CFRP) for repair and renewal of large-diameter pipelines in the United States has grown significantly over the past decade.  The increase is due to several factors, nearly all connected to the benefits of composites, including long-term durability and trenchless construction process.   
 
As economic factors continue to impact owners of large-diameter pipelines in the water/wastewater, industrial and power generation sectors, asset management programs have become more robust.  The result of this has been more information available to owners about the condition of their pipelines, life cycle expectations and specific areas of distress and damage.   
 
The trend that has emerged from this increase in information is that owners have moved away from wholesale pipeline replacement based on life cycle toward implementing more progressive approaches to maximize their investments.  These include “find and fix” and proactive renewal, both of which include periodic condition assessment and implementation of precision repair or renewal based upon prioritized needs balanced with available budgets.  
 
In these scenarios, where specific segments of a pipeline or pipelines are identified as distressed, CFRP offers an elegant solution to deliver a fully structural 50-year service life extension with minimal construction disruption. The main drivers for its utilization are CFRP’s trenchless installation method and that it has little to no impact on hydraulic performance. CFRP is chosen mainly to meet needs in areas of high congestion, either urban or within complex industrial and power plant environments.  
 
Over the past decade significant advancements have also been made in market acceptance and adoption of composite repairs of large-diameter pipelines.  In 2018 American Water Works Association (AWWA) published C305-18, a new standard for CFRP Renewal and Strengthening of Prestressed Concrete Cylinder Pipe (PCCP), which took nine years to develop.   
 
Along with the AWWA C305 standard, American Society of Mechanical Engineers (ASME) also has a code case in development for Internal Repair of Class 2 & 3 Buried Piping Using Carbon Fiber Composite Materials.  The code case has been preceded by multiple US Nuclear Regulatory approvals of the use of CFRP for large-diameter pipeline renewal on an exemption basis, which have helped to drive increased adoption within the nuclear industry.   
 
Development of industry standards for composite repairs of large-diameter pipelines is based upon extensive research and development, and full-scale testing.  This includes materials, durability, and full-scale pressure testing which will be discussed during this presentation.   
 
The presentation will focus on how composite repairs of large-diameter pipelines have impacted the longevity and reliability of critical infrastructure for large diameter pipeline owners, with multiple case histories highlighted.  Workshop participants will learn about the options analysis process - both how and why CFRP was selected - and then how each of the highlighted owners have made industry-wide impacts helping to grow the use of composites.

Location: Building 19, Level 3, Hall 1-2.