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.

Download or read book An Automated Framework for Defect Detection in Concrete Bridge Decks Using Fractals and Independent Component Analysis written by Fadi Abu-Amara and published by . This book was released on 2010 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge decks deteriorate over time as a result of deicing salts, freezing-and-thawing, and heavy use, resulting in internal defects. According to a 2006 study by the American Society of Civil Engineers, 29% of bridges in the United States are considered structurally deficient or functionally obsolete. Ground penetrating radar (GPR) is a promising non-destructive evaluation technique for assessing subsurface conditions of bridge decks. However, the analysis of GPR scans is typically done manually, where the accuracy of the detection process depends on the technician's trained eye. In this work, a framework is developed to automate the detection, locailzation, and characterization of subsurface defects inside bridge decks. This framework is composed of a fractal-based feature extraction algorithm to detect defective regions, a deconvolution algorithm using banded-ICA to reduce overlapping between reflections and to estimate the depth of defects, and a classification algorithm using principal component analysis to identify main features in defective regions. This framework is implemented and simulated using MATLAB and GPR real scans of simulated concrete bridge decks. This framework, as demonstrated by the experimental results, has the following contributions to the current body of knowledge in ground penetrating radar detection and analysis techniques, and in concrete bridge deck condition assessment: 1) developed a framework that integrated detection, localization, and classificationof subsurface defects inside concrete bridge decks, 2) presented a comparison between the most common fractal methods to determine the most suitable one for bridge deck condition assessment, 3) introduced a fractal-based feature extraction algorithm that is capable of detecting and horizontally labeling defective regions using only the underlying GPR B-scan without the need for a training dataset, 4) developed a deconvolution algorithm using EFICA to detect embedded defects in bridge decks, 5) introduced an automated identification methodology of defective regions which can be integrated into a CAD system that allows for better visual assessment by the maintenance engineer and has the potential to eliminate human interpretation errors and reduce condition assessment time and cost, and 6) presented an investigation and a successful attempt to classify some of the common defects in bridge decks.

Download or read book Ground Penetrating Radar Bridge Deck Investigations Using Computational Modeling written by and published by . This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrastructure in the United States is failing. According to a 2005 study by the American Society of Civil Engineers over a quarter of the bridges are structurally deficient or functionally obsolete. Condition assessment without the assistance of subsurface sensing techniques leads to poor detection and quantification of damage because much of the damage and precursors to damage is hidden beneath the surface. Ground Penetrating Radar (GPR) a popular choice for bridge deck assessment, depends on a subjective process, which is the trained eye of a technician. The ability to simulate a GPR investigation provides insight into the response from bridge deck elements, as well as the interaction among the elements and changes due to the presence of an anomaly and supports defect detection. A subsurface modeling tool is developed with physical modeling components available for general applications but extended to meet specific requirements for geometric modeling of civil infrastructure. The simulation component implements the 2-dimensional Finite Difference Time Domain (FDTD) method for electromagnetic modeling. Comparisons between 2D and 3D simulations show that, for bridge deck analysis, 2D modeling is adequate for condition assessment. A model-based assessment augments the conventional approach to analysis by using iterative computational models to reconstruct the bridge deck in a healthy condition. To identify areas of suspect condition, the response from the computed healthy deck can be compared to the response collected in the field. The effect of the presence of rebars on the scattering from an anomaly can be significant, and is not easily removed from GPR data. In the computational model, the strong scattering rebars are replaced with an excitation source that results in wave propagation equivalent to the scattering from the rebar. This technique makes the GPR bridge deck problem better suited to the traditional inversion algorithms that are often complicated by strong scatterers. Through experimentation, the GPR antenna can be characterized to determine a virtual sensor for the 2D FDTD model. The resulting sensor allows for a significantly smaller geometry, which saves time and computational resources while reducing differences in propagation associated with using a 2-dimensional instead of 3-dimensional model.

Download or read book Condition Assessment of Concrete Bridge Decks Using Ground Penetrating Radar written by Kien Dinh and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a Condition Assessment Method of Deteriorated Bridge Decks Based on GPR Data and Structural Response written by Dipesh Donda and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridges are at the heart of transportation systems connecting the roads to and between the mainlands. Thus, bridges are an integral part of the economic growth of any country. They are subjected to dynamic loads of the vehicles and the environmental effects. These loads cause stress and strain cycles causing its deterioration by initiating microcracking. The deterioration is then accelerated due to the chloride attack which causes the corrosion of the steel reinforcement resulting in cracking and delamination of concrete and ultimately leads to failure. It is essential to analyze the bridge with its actual condition which is difficult with a visual inspection. This analysis can help in determining the degree of repairs needed and an approximate idea about its service life. The development of the Non-Destructive Test (NDT) methods helps assess the condition of the bridge without any kind of damage to the original structure. In the past few decades, the Non-Destructive Evaluation (NDE) with the help of Ground Penetration Radar (GPR) has gained popularity due to its ease in the evaluation of the larger areas such as bridge deck and parking lot in a shorter amount of time with sufficient training. The NDE using GPR for Structural Health Monitoring (SHM) has been still evolving with new improvements in its technology as well as the development of new methods for the analysis of its data. A positive step towards detecting the subsurface materials present in the cracks has been undertaken in this study. A methodology to detect the subsurface cracks/gaps in concrete using GPR has been developed here by preparing three concrete samples of dimensions 50 x 25 x 5 cm3, 50 x 25 x 10 cm3, and 50 x 25 x 20 cm3 in the laboratory. The detection of reinforcement of 6 mm, 10 mm, 18 mm, 20 mm diameter, as well as a 21.8 mm Fiber Reinforcement Polymer (FRP) bar, are studied along with the detection of the air gap, water gap, and gap with the salt solutions of thickness 3 mm, 4 mm, 4.8 mm, 5.8 mm and 8.8 mm under the depth of 5 cm, 10 cm, and 15 cm. The amplitude values of these parameters are studied, and a comparison is made to check the ability of GPR to detect this material in cracks and/or delamination with changes in depths. This will be helpful in analyzing the GPR data with more reliability. Along with this, a non-linear finite element model (FEM) of a bridge superstructure using a fiber element is developed. The FE model of the bridge deck is updated and analyzed using a GPR defect map. This procedure of model updating is less tedious than the previous method available in the literature and proves to be time-saving. This model updating procedure will prove to be helpful in estimating the capacity of the bridge and make a prediction for future deterioration with the help of NDE methods (here GPR).

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.

Download or read book Detection of Sub surface Anomalies in Concrete Bridge Decks Using Ground Penetrating Radar written by Vasudev A. Bhandarkar and published by . This book was released on 1993 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ground Penetrating Radar based Deterioration Assessment of Bridge Decks written by Ahmad Shami and published by . This book was released on 2015 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASCE report card 2013 rated bridges at a grade of C+, implying their condition is moderate and require immediate attention. Moreover, the Federal Highway Administration reported that it is required to invest more than $20.5 billion each year to eliminate the bridge deficient backlog by 2028. In Canada 2012, more than 50% of bridges fall under fair, poor, and very poor categories, where more than $90 billion are required to replace these bridges. Therefore, government agencies should have an accurate way to inspect and assess the corrosiveness of the bridges under their management. Numerical Amplitude method is one of the most common used methods to interpret Ground Penetrating Radar (GPR) outputs, yet it does not have a fixed and informative numerical scale that is capable of accurately interpreting the condition of bridge decks. To overcome such problem, the present research aims at developing a numerical GPR-based scale with three thresholds and build deterioration models to assess the corrosiveness of bridge decks. Data, for more than 60 different bridge decks, were collected from previous research works and from surveys of bridge decks using a ground-coupled antenna with the frequency of 1.5 GHz. The amplitude values of top reinforcing rebars of each bridge deck were classified into four categories using k-means clustering technique. Statistical analysis was performed on the collected data to check the best-fit probability distribution and to choose the most appropriate parameters that affect thresholds of different categories of corrosion and deterioration. Monte-Carlo simulation technique was used to validate the value of these thresholds. Moreover, a sensitivity analysis was performed to realize the effect of changing the thresholds on the areas of corrosion. The final result of this research is a four-category GPR scale with numerical thresholds that can assess the corrosiveness of bridge decks. The developed scale has been validated using a case study on a newly constructed bridge deck and also by comparing maps created using the developed scale and other methods. The comparison shows sound and promising results that advance the state of the art of GPR output interpretation and analysis. In addition, deterioration models and curves have been developed using Weibull Distribution based on GPR outputs and corrosion areas. The developed new GPR scale and deterioration models will help the decision makers to assess accurately and objectively the corrosiveness of bridge decks. Hence, they will be able to take the right intervention decision for managing these decks.

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.

Download or read book Ground penetrating Imaging Radar Development for Bridge Deck and Road Bed Inspection written by and published by . This book was released on 1993 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ground-penetrating imaging radar (GPIR) is proposed for large-area inspection of concrete and concrete/asphalt composite bridge decks and roadways. This technique combines ground-penetrating radar (GPR) with unique image reconstruction algorithms developed for identification and characterization of subsurface flaws and structural features. New data acquisition hardware and image reconstruction techniques, under development at LLNL, offer the possibility for reliable and efficient, high-resolution subsurface imaging through the use of improved ultra-wideband transmitters, antennas, and arrays, and enhanced image- and signal-processing software. A field test of a limited-capability prototype system is planned for FY-93, as is completion of a conceptual design for a practical inspection system. A follow-on program for FY-94 would focus on development and demonstration of an advanced bridge inspection system prototype based on the conceptual design completed during FY-93.

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:

Download or read book Ground Penetrating Radar Technique for Bridge Deck Inspection written by Layane Hamzch and published by . This book was released on 2014 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The rapid growth of infrastructure in the UAE has caused a proportional growth in the transportation system. Bridges are among the major elements in the transportation system that requires continuous monitoring and maintenance over time. Replacement of bridges is expensive; hence it is desirable to assess damage using a cost effective maintenance strategy. Therefore, nondestructive testing techniques provide an efficient and feasible method for detecting defects in bridges in a quick manner. Several surveys have shown that ground penetrating radar (GPR) has the potential to be adopted as a non-destructive inspection technique. This work presents an experimental investigation of mix variation, and environmental conditions effects on the detectability of defects using GPR."--Abstract.

Download or read book The Detection of Common Concrete Bridge Deck Defects Using Thermography Impact Echo and Ground Penetrating Radar written by Saleh Z. Nabulsi and published by . This book was released on 2005 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Blind Source Separation for Feature Detection and Segmentation in Ground Penetrating Radar GPR Imaging of Concrete Bridge Decks for Non destructive Condition Assessment written by Vincent Krause and published by . This book was released on 2015 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete bridge decks require periodic condition assessment and preventive maintenance to extend their useful lifespan. Nondestructive evaluation methods such as Ground Penetrating Radar (GPR) are slowly beginning to replace or complement the manual (visual) assessment of bridge conditions for detecting defects at their early stages. However, GPR scans of bridge decks are frequently cluttered with high amplitude reflections from known parts of the bridge deck, which make the detection of defects low amplitude reflections difficult. One such known part is the embedded steel reinforcement bars known as rebar. This dissertation presents a novel approach to the automated detection of defects in concrete bridge decks by removing known reflections such as rebar from GPR scans of reinforced concrete bridge decks. The algorithm detects reflections from rebar with a frequency-domain pulse detection method, groups detected pulses into clusters, interpolates synthetic rebar reflections based on each cluster, and subtracts the synthetic rebar reflection from the original GPR scan data. This algorithm will facilitate the automated, non-destructive condition assessment of bridge decks.

Download or read book Bridge Deck Assessment Using Visual Inspection Ground Penetrating Radar Portable Seismic Property Analyzer ultrasonic Surface Wave Hammer Sounding and Chain Drag written by Abdullah Hadi Zaid Alhaj and published by . This book was released on 2018 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Integrated non-destructive techniques were utilized to assess the condition of a reinforced concrete bridge deck. There were two main objectives accomplished. The first objective was to assess the integrity of the reinforced concrete bridge deck using four non-destructive techniques, namely visual inspection, ground penetrating radar, portable seismic property analyzer-ultrasonic surface wave, and hammer sounding and chain drag. Visual inspection data were used to identify signs of deterioration on surface of the bridge deck such as cracking, concrete leaching, and reinforcement corrosion. Ground penetrating radar data were used to determine the relative condition of the bridge deck. However, due to the significant differences in depth of the embedded reinforcements, ground penetrating radar data were not useful in terms of assessing the overall condition of the bridge deck. Portable seismic property analyzer-ultrasonic surface wave data were used to determine the concrete quality of the bridge deck by estimating average Young's modulus (elastic modulus). Hammer sounding and chain drag data were used to identify non-delaminated and severe delaminated areas in the bridge deck. The second objective was to demonstrate the effect of temperature and moisture content changes on ground penetrating radar signal amplitude. Ground penetrating radar signal amplitude variations associated with different weather condition of temperature and moisture changes were evaluated. Ground penetrating radar signal amplitude was increasingly attenuated during low temperature and high moisture content. In contrast, ground penetrating radar signal amplitude was decreasingly attenuated during high temperature low moisture content"--Abstract, page iii.

Download or read book Detection of Progressive Deterioration in Bridge Decks Using Ground Penetrating Radar written by Kenneth R. Maser and published by . This book was released on 1988 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridge Deck Inspection and Dowel Bar Detection written by Wooyoung Kim and published by . This book was released on 2003 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The present study is comprised of two separate GPR case studies on a bridge deck and a concrete pavement respectively. These typical concrete structures were investigated using GPR with several objectives: 1) to find the reason of discrepancies between GPR results and the results of the other tests through bridge deck inspection, 2) to investigate the bridge deck under various weather conditions, 3) to determine the relative spatial locations of the imbedded dowel bars in the new concrete pavement, and finally 4) to evaluate the present capabilities of GPR technology including survey scheme and analysis through these two case studies."--Abstract, p. iii.