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Book Determination of Bridge Deck Subsurface Anomalies by Infrared Thermography and Ground Penetrating Radar

Download or read book Determination of Bridge Deck Subsurface Anomalies by Infrared Thermography and Ground Penetrating Radar written by David G. Alt and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to evaluate the use of infrared (IR) thermography and ground penetrating radar (GPR) to find subsurface anomalies, delaminations and de-bonding, on asphalt concrete overlaid concrete bridge decks. The traditional "chaining" method is a less effective option for finding subsurface defects after an overlay is in place. An IR thermographic and GPR (IR/GPR) evaluation was conducted on the I-70 Polk-Quincy viaduct in 1993. The results were compared to other studies conducted to check for subsurface anomalies.

Book Review of Progress in Quantitative Nondestructive Evaluation

Download or read book Review of Progress in Quantitative Nondestructive Evaluation written by Donald O. Thompson and published by American Inst. of Physics. This book was released on 2002-05-24 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series provides a comprehensive review of the latest research results in quantitative nondestructive evaluation (NDE). Part A of Volume 21 details the development of nondestructive evaluation techniques. Part B addresses advances in materials characterization, new applications, and reliability.

Book Bridge Deck Inspection Utilizing Infrared Thermal Imaging Technique

Download or read book Bridge Deck Inspection Utilizing Infrared Thermal Imaging Technique written by Sharef Farrag and published by . This book was released on 2014 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Infrared Thermography (IRT) is a promising Non-destructive Evaluation (NDE) technique that has been widely used in bridge deck inspection. It is a quick and easy alternative to provide preliminary information of possible defected areas in bridge decks. However, detection capabilities and sensitivity to environmental conditions and material properties impose some challenges for the application of IRT. In this study, the effect of varying concrete mixtures on passive IRT was investigated. Four different concrete mixtures, conventional, high-strength, self-consolidated and lightweight concrete, were included in the evaluation. Various defects with relatively small sizes and depths were simulated and planted in cast-in-place slabs. The casting and testing took place in the United Arab Emirates (UAE), which is considered a hot weather region. The defected specimens were imaged, and the images were compared to non-defected specimens to enhance the judgment on defect detection. Thermal conductivity of each mix was estimated using the Maxwell- Eucken 2-phase composite material model, and Rapid Chloride Penetration was tested and used as an indication of density. The slabs were imaged during the cooling cycle. Results indicated that mix variation had a significant effect on IRT. High strength concrete achieved the highest detection possibility among the mixes. Furthermore, results showed that the higher the density and thermal conductivity coefficient, the better the defect detection using IRT at ideal imaging conditions is. For the UAE, ambient conditions are favorable for passive IRT, as the results indicated minimal sensitivity to wind, relative humidity, and temperature as opposed to other locations in the world where passive IRT would not be applicable. Nevertheless, because of IRT limitations, it would be better employed as a health monitoring technique with baseline comparisons rather than an independent primary inspection NDT tool for bridges."--Abstract.

Book Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography

Download or read book Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography written by American Society for Testing and Materials. Committee D04 on Road and Paving Materials and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography

Download or read book Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography written by American Society for Testing and Materials. Committee D04 on Road and Paving Materials and published by . This book was released on 2007 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Advancements in Evaluating Reliability of Nondestructive Technologies for the Detection of Subsurface Fracture Damage in R C Bridge Decks

Download or read book Advancements in Evaluating Reliability of Nondestructive Technologies for the Detection of Subsurface Fracture Damage in R C Bridge Decks written by Ali Abed Sultan and published by . This book was released on 2017 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last few decades, many efforts have been made to assess the reliability of nondestructive evaluation (NDE) technologies used for the detection of subsurface damage in concrete bridge decks. During these efforts, reliability of NDE technologies has either been described anecdotally, or been solely relegated to the probability of detection (POD) or accuracy estimation. Although these indices are important, most of the previous work did not take into account the probability of false alarm (POFA) of NDE technologies, nor did they investigate the reliability considering multiple threshold settings throughout test results. In addition, the existing body of research has used a limited physical sampling such as coring to validate NDE results. Consequently, the assessments were rather controversial, and there was no general agreement about the reliability of such technologies. Because most diagnosis systems are characterized by noisy data and less than perfect detection characteristics, reliability is to be carefully assessed considering all possible diagnosis output with multiple threshold settings within practical range of applications. In other words, when NDE data do not fall into either of the two obviously defined categories: true positive (TP), meaning the NDE data indicates a defect and there is a defect, or true negative (TN), meaning the NDT data indicates no defect and there is no defect, reliability analysis should also include the two types of incorrect indications: failure to give a positive indication in the presence of a defect (false negative, FN) and giving a positive indication when there is no defect (a false alarm or false positive, FP). The \three decades of NDI reliability assessments" report developed by Karta Technologies, Inc. in 2000 under supervision of the Air Force NDI Office stated that POD alone cannot describe the reliability of NDE technologies unless the probability of false alarm (POFA) is also considered in the analysis. POFA may be induced by noise with several possible sources: human, nature of phenomenon to be measured, and environmental conditions. The report covered nearly 150 reports and manuscripts from over 100 authors. However, a review of research literature reveals that little theoretical work on the reliability assessment in terms of both POD and POFA has been undertaken since then. In this research, the reliability of impact echo (IE), infrared thermography (IRT), and ground penetration radar (GPR) technologies for the detecting of subsurface damage in concrete plate-like members is assessed by using a statistical analysis method called receiver operating characteristic (ROC). The proposed analysis method has the capability to integrate POD and POFA indices over a wide range of decision threshold settings in a single curve, which is useful in assessing trade-off in choosing a threshold and for quantitatively comparing the performance of NDE technologies. This methodology for assessing NDE reliability is intended to provide a more effective means of comparing different technologies used in civil engineering applications, to make the evaluation process of a quantitative scheme, to reduce subjectivity and variability in interpreting NDE data, and to improve sensitivity to extract more information from NDE data. Area under ROC curve (AUC), which is interpreted as the probability of correctly classifying an arbitrarily pair of negative and positive test points, can provide for the desired quantitative reliability index, which can be used to compare the performance of one NDE technology to another. Results of this research obtained from ROC analysis indicate a great ability of IE and IR in detecting subsurface fracture damage such as delamination and debonding. In both technologies, there exist some threshold settings that can provide for a relatively high POD with very low POFA, and consequently, the areas under their ROC curves were very high. Data obtained from GPR testing, on the other hand, indicates that GPR technology has a very limited ability to detect physical damage such as subsurface delamination. This conclusion contrasts with that been argued by a large body of the previous work. However, GPR showed a good sensitivity to the presence of corrosive environments such as moisture and chloride when the concentrations of these factors are above some threshold values that may facilitate the initiation of steel reinforcement corrosion.

Book Rehabilitating and Repairing the Buildings and Bridges of the Americas

Download or read book Rehabilitating and Repairing the Buildings and Bridges of the Americas written by Daniel A. Wendichansky and published by . This book was released on 2002 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection contains 17 papers presented at a workshop, Rehabilitating and Repairing the Buildings and Bridges of the Americas: Hemispheric Workshop on Future Directions, held in Mayaguez, Puerto Rico, April 23-24, 2001.

Book Development of a Procedure for the Detection of Subsurface Defects in Bridge Deck Joint Armor Using Ground Penetrating Radar and Seismic Properties Analysis

Download or read book Development of a Procedure for the Detection of Subsurface Defects in Bridge Deck Joint Armor Using Ground Penetrating Radar and Seismic Properties Analysis written by Larry Lance Rickard and published by . This book was released on 2011 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seeks to extend the use of three non-destructive testing and evaluation (NDT/E) techniques, high-density surveying, ground penetrating radar, and seismic properties analysis, to the detection and quantification of subsurface defects and anomalies in and around bridge deck armor. Investigates and documents any challenges peculiar to these techniques with regard to armored deck joints, as well as their potential as alternatives or adjuncts to conventional NDT/E techniques.

Book Deep Learning and Infrared Thermography based Subsurface Damage Detection in a Steel Bridge

Download or read book Deep Learning and Infrared Thermography based Subsurface Damage Detection in a Steel Bridge written by Rahmat Ali and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aging and deterioration of bridge infrastructure is becoming a serious issue around the world. In this research, a new deep-learning-based method is proposed to detect subsurface damage in the steel elements of a bridge using thermography, without physical contact. Thermal images of the structural steel elements on the Arlington Bridge in Winnipeg, Manitoba, were captured using an uncooled microbolometer and were then used to train and validate a deep inception neural network; a maximum testing accuracy of 96% was achieved. Next, ultrasonic pulse velocity tests were conducted for validating thermal-image-based subsurface damage detection, and a contour map of the sections was plotted and compared with a deep-learning-based results. This research demonstrates that the combination of infrared thermal technology with a deep neural network is a practical approach to autonomously detecting subsurface damage in the elements of a steel bridge, with minimum human intervention.

Book Infrared Inspection of Composite reinforced Concrete Structures

Download or read book Infrared Inspection of Composite reinforced Concrete Structures written by James Phillip Nokes and published by . This book was released on 2001 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Ohio Department of Transportation has been evaluating the use of composite reinforcements to enhance the safety margins in concrete deck bridges. A critical aspect of the retrofitting process is ensuring that the composite material remains bonded to the concrete beams that are subjected to prolonged exposure to the elements. The goal of this program was to select and demonstrate an appropriate nondestructive evaluation (NDE) technique for composite reinforced structures. Thermography was chosen as the inspection technique because it has been well established within the aerospace industry for the detection of flaws and damage within composite structures. A field-portable thermographic technique was developed during this program. Two Coshocton County, Ohio bridges were inspected three times over a two-year interval. The results of the program showed that IR thermography can be used to reliably detect and size debonds with an area six square inches or greater in composite retrofit systems. The IR data has the potential to detect and monitor debond growth. In the current set of data, no indications were noted that were longer than 1 ft. along the axis of the beam and 6" across the width of the beam.