QA/QC Procedures for Structural Rehabilitation of PCCP with CFRP Composites

摘要

This paper presents the experience of the design and implementation of new Quality Assurance andQuality Control Web-based System for the structural rehabilitation of PCCP with CFRP composites withinWashington Suburban Sanitary Commission.The majority of the Washington Suburban Sanitary Commission (WSSC) large diameter water transmission mainsare made of Prestressed Concrete Cylinder Pipes (PCCP). This is common picture for most municipalitiesnationwide. Many of the transmission mains have been in service for well over fifty years. As these pipes age, therisk of failure increases. One of the standard ways to repair PCCP pipelines is to use Carbon Fiber ReinforcedPolymer (CFRP) composites. The installation of the internal CFRP structural liner inside the pipe includes manyoperations, such as: preparation of the pipe, fiber saturation, etc. Each step of the technological process, if done withdeviation from the specification, may compromise the structural integrity of the repair. Because the volume of suchrepairs is constantly growing, Quality Assurance and Quality Control (QA/QC) procedures for the structuralrehabilitation of the PCCP with CFRP composites become more critical. The QA process requires quality control foreach operation, designed to ensure that the development process will adequately meet all of the specifications.With the new PCCP rehabilitation program, Washington Suburban Sanitary Commission has reinforced many milesof main pipelines and recovered more than a hundred pipe sections within the last two years using CFRP. Constantlyimproving all procedures of the rehabilitation process from the internal inspection and evaluation of the ConditionAssessment results, through design of the reinforcement, and ending with installation of the required amount of FRPlayers, WSSC Engineering developed a web-based QA/QC system.The newly implemented Quality Assurance system helps to control the ongoing FRP installation and instantlyconfirm the compliance of the installed components of the structural system to the approved Specifications. Therecording of each stage of the rehabilitation project for every pipe section will help to monitor the pipeline andcoordinate future maintenance and repairs.