Gary J. Weil

Infrared-thermography-based pipeline leak detection systems

Computerized Infrared Thermographic pipeline inspection is now a refined and accurate process having been thoroughly proven to be an accurate, cost effective, and efficient technology during a 10 year development and testing process. The process has been used to test pipelines in chemical plants, water supply systems, steam lines, natural gas pipelines and sewer systems. Its non-contact, nondestructive ability to inspect large areas from above ground with 100% coverage and to locate subsurface leaks as well as the additional capability to locate voids and erosion surrounding pipelines make its testing capabilities unique. This paper will detail the development of computerized infrared thermographic pipeline testing along with case histories illustrating its implementation problems and successes and innovations anticipated for the future.

Nondestructive testing of the concrete roof shell at the Seattle Kingdome

As part of major rehabilitation and repair of the 360,000 square foot reinforced concrete shell roof of the Kingdome in Seattle, a comprehensive nondestructive testing program reemploying IR thermographic and impact echo techniques was performed to evaluate various in-situ concrete conditions. Questions had developed regrading the extent and significance of areas that exhibited honeycomb or paste voiding near reinforcing steel on the underside of the roof shell following removal of acoustical ceiling tile. The objective of the nondestructive testing program was to identify locations of large, planar-type regions of deep voiding or delamination associated with the consolidation and reinforcement placement conditions. The combined use of IR thermography and impact echo techniques allowed for efficient and effective scanning of the large roof shell structure entirely from the interior. Anomalous areas identified by the testing were verified by additional nondestructive testing, visual inspection, local exploratory openings and core samples. Based on results of the nondestructive testing, a broad-based repair program was implemented to correct conditions of near surface voiding and through-thickness honeycomb. Repairs consisted of the application of structural shortcrete to restore integrity in thickened, key load transfer zones of the shell and the overall treatment of the entire underside of the shell with sprayed mortar. This paper present an overview of IR thermographic testing theories and discusses the specific applications, logistics, and result from testing of the concrete shell of the Seattle Kingdome.

Nondestructive remote sensing of hazardous waste sites

For the past hundred years, government and private industry have produce hazardous waste in ever increasing quantities. These untold millions of tons of environmentally dangerous wastes have been disposed of by undocumented burial, simple carelessness and purposeful abandonment. Society has recently dictated that before new construction may be initiated, these wastes must be found and cleaned up. The first step is to locate these undocumented waste depositories. This paper describes how the non-contact, nondestructive, remote sensing techniques, of Computer Enhanced Infrared Thermography and Ground Penetrating Radar, may be used to detect buried waste sites, buried tanks/pits, and tank/pit leak plumes. This technology may be used from mobile vehicles, helicopters or man-portable system and is able to cover tens of acres per day depending upon the system method used. This proven, but relatively new technology, will be described in theory, by procedure and the use of case studies based upon successful projects during the last ten years.

Infrared thermographic detection of buried grave sites

Since time began, people have been born and people have died. For a variety of reasons grave sites have had to be located and investigated. These reasons have included legal, criminal, religious, construction and even simple curiosity problems. Destructive testing methods such as shovels and backhoes, have traditionally been used to determine grave site locations in fields, under pavements, and behind hidden locations. These existing techniques are slow, inconvenient, dirty, destructive, visually obtrusive, irritating to relatives, explosive to the media and expensive. A new, nondestructive, non-contact technique, infrared thermography has been developed to address these problems. This paper will describe how infrared thermography works and will be illustrated by several case histories.

Steel plant predictive-maintenance programs utilizing IR NDT

Abstract not available.