A New Tool for Concrete Cylinder Force Main Condition Assessment - External Electromagnetic Thickness Testing

Presentation Description: A new tool is available for concrete cylinder force main condition assessment: electromagnetic (EM) thickness testing. This tool does not require destructive methods that increase risk and defeat the purpose of assessment, nor does it require deployment of equipment on the inside of the pipe. V&A is piloting a technique developed in the oil and gas industry to use an EM probe on the outside of the pipe to measure metal thickness. Ross Valley Sanitary District's seven-mile force main system is about 42% reinforced concrete cylinder pipe (RCCP), with a steel cylinder surrounded by cement and outside steel reinforcing, installed between 1958 and 1986. RVSD would prefer avoidance of costly replacement if a non-destructive condition assessment technique would indicate more years of remaining service. The application of EM testing to a section of RCCP pipe along a known corrosion gradient will be presented, along with costs, equipment, procedures and results, and the potential application of EM testing in RVSD's broader condition assessment program will be discussed.