Application Of Ground Penetrating Radar Gpr For Bridge Deck Condition Assessment Using A 15 Ghz Ground Coupled Antenna
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Author | : Amos Wamweya |
Publisher | : |
Total Pages | : 0 |
Release | : 2009 |
Genre | : Bridges |
ISBN | : |
"This study is a GPR-based assessment of three bridge decks, two with a hot bituminous wearing surface and one with a bare concrete slab. The primary objectives of this study were: 1) to assess the integrity of the three bridge decks using a 1.5 GHz ground-coupled GPR antenna, and 2) to evaluate the utility of the 1.5 GHz ground-coupled antenna for bridge deck investigations. Core control (chloride ion concentration data and core integrity data) and visual inspection were used as interpretive constraint. The acquired GPR data were interpreted, and two plan view maps were generated. One depicts the magnitude of the reflections from the uppermost mat of rebar, and the second shows the arrival time of these reflections. Analysis of the GPR data and core control indicates that the magnitude of the reflected GPR signal from the uppermost mat of rebar is a direct function of concrete integrity. Higher magnitude reflections indicate higher quality concrete. To a lesser extent, the arrival time of the reflected energy is also indicative of concrete quality. Faster arrival times generally indicate higher quality concrete. Exceptions to this rule occur where the depth to the top layer of rebar varies. In this study, relative reflection amplitudes of less than 3000 on the bare concrete bridge and less than 5000 on the bituminous surface bridges indicate severe deterioration. Core control data was interpreted based on chloride ion corrosion threshold. Corrosion of rebar occurs once chloride ions content adjacent to the rebar reaches a threshold of approximately 0.033% to 0.04% by weight of concrete (or 330 ppm to 400 ppm). The GPR data correlates well with the core control, indicating that the 1.5 GHz antenna is an effective tool for assessing the condition of bridge decks"--Abstract, leaf iii
Author | : Andrea Benedetto |
Publisher | : Springer |
Total Pages | : 373 |
Release | : 2015-04-07 |
Genre | : Science |
ISBN | : 3319048139 |
This book, based on Transport and Urban Development COST Action TU1208, presents the most advanced applications of ground penetrating radar (GPR) in a civil engineering context, with documentation of instrumentation, methods and results. It explains clearly how GPR can be employed for the surveying of critical transport infrastructure, such as roads, pavements, bridges and tunnels and for the sensing and mapping of underground utilities and voids. Detailed attention is also devoted to use of GPR in the inspection of geological structures and of construction materials and structures, including reinforced concrete, steel reinforcing bars and pre/post-tensioned stressing ducts. Advanced methods for solution of electromagnetic scattering problems and new data processing techniques are also presented. Readers will come to appreciate that GPR is a safe, advanced, non destructive and noninvasive imaging technique that can be effectively used for the inspection of composite structures and the performance of diagnostics relevant to the entire life cycle of civil engineering works.
Author | : Rexford M. Morey |
Publisher | : Transportation Research Board |
Total Pages | : 48 |
Release | : 1998 |
Genre | : Technology & Engineering |
ISBN | : 9780309061100 |
This synthesis will be of interest to state Department of Transportation (DOT) geotechnical, bridge, and pavement engineers, engineering geologists, consultants involved with ground penetrating radar (GPR) investigations for state DOTs, and researchers. It describes the current state of the practice of using GPR for evaluating subsurface conditions for transportation facilities. This was accomplished by conducting a literature search and review and an extensive survey of U.S. and Canadian transportation agencies and practitioners, as well as limited international information collection. GPR is a noninvasive nondestructive tool used in transportation applications such as evaluation and characterization of pavement systems, soils, and environmental problems. This report of the Transportation Research Board presents information on the principles, equipment, logistics, applications, and limitations of GPR pertaining to transportation applications. Selected case studies for which ground truth information is available are presented. In addition, an extensive bibliography and glossary are provided as well as appending information about GPR manufacturers from their literature.
Author | : Aleksey Kamilevich Khamzin |
Publisher | : |
Total Pages | : 194 |
Release | : 2015 |
Genre | : Bridges |
ISBN | : |
"Ground penetrating radar (GPR) data were acquired across four bridge decks with the objective of developing an advanced workflow for GPR operation that would allow the bridge owners to estimate repair quantities for certain bridge decks, based on GPR data. The primary contributions from this research are as follows: 1. It was demonstrated that the conditions of bridge decks can be cost-effectively and efficiently assessed using the GPR tool. 2. The GPR tool's ability to provide rapid and reliable results in comparison with conventional bridge deck condition assessment techniques was established. 3. The qualitative and quantitative relationships between the GPR reflection amplitude and depth of concrete degradation were analyzed to develop an effective technique to estimate the amount of deteriorated concrete present in a particular bridge deck; this technique could enable bridge owners to use the GPR tool (only) to estimate the thickness of concrete that would be removed by processes such as hydro demolition. 4. The air-launched and ground-coupled GPR systems were compared in terms of accuracy of data acquisition and reliability of results. It was determined that air-launched GPR is a reliable tool for the fast and cost-effective assessment of bridge decks. This work is new and important because it extends the traditional use of the GPR technique and presents the advanced approach for data interpretation and concrete material removal estimation, especially in areas where deterioration was not visually exposed"--Abstract, page iii.
Author | : Ahmad Shami |
Publisher | : |
Total Pages | : 138 |
Release | : 2015 |
Genre | : |
ISBN | : |
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.
Author | : |
Publisher | : |
Total Pages | : 218 |
Release | : 2005 |
Genre | : Bridges |
ISBN | : |
Author | : Lesley Sneed |
Publisher | : |
Total Pages | : 49 |
Release | : 2015 |
Genre | : Concrete bridges |
ISBN | : |
This study demonstrated the utility of the air launched ground penetrating radar (GPR) tool in terms of evaluating the condition of MoDOT bridge decks. The objective was to confirm that the air-launched GPR tool can be implemented as a part of a long-term program that enables faster, better, and more cost-effective assessments of MoDOT bridge decks. Ten bridge decks were investigated using an air-launched GPR system. Four of the bridge decks investigated were previously investigated using a ground-coupled GPR system, and results from those four bridge decks served as ground truth for the air-launched GPR interpretations. Findings show reasonably good spatial correlation between the ground-coupled GPR and air-launched GPR datasets in terms of deteriorated regions and overall percentages of deteriorated regions in terms of bridge deck surface area. Apparent discrepancies between the air launched and ground-coupled GPR interpretations can be attributed to several factors, including interpolation between adjacent GPR traverses, differences in signal attenuation due to different antenna frequencies, and differences in signal resolution due to different distance from the antenna to the embedded reinforcing steel. Recommendations for optimum acquisition, processing, and interpretation parameters for air-launched GPR reconnaissance-style assessment were provided as part of this study.
Author | : |
Publisher | : |
Total Pages | : 748 |
Release | : 2004 |
Genre | : Geophysics |
ISBN | : |
Designed to provide highway engineers with a basic knowledge of geophysics and nondestructive (NDT) methods for solving specific transportation related problems.
Author | : Daniel E. Diaz |
Publisher | : |
Total Pages | : 308 |
Release | : 2018 |
Genre | : |
ISBN | : |
As the nation's infrastructure continues to age, there is a need to effectively and economically monitor and inspect bridges. With the introduction of non-destructive testing technologies such as Ground Penetrating Radar (GPR) for condition assessment of bridge decks, states will be better equipped to inspect, assess, and prioritize transportation funding to maintain, preserve, and improve infrastructure. The objective of the research is to improve the condition assessment of bridge decks through the use of GPR which can increase the speed, effectiveness, and accuracy of inspections. The non-destructive evaluation technique provides information that can be used to identify the potential amount of internal deterioration of a concrete bridge deck that cannot be identified with a visual inspection. As in many other states, New Mexico currently uses the chain drag method in which the inspection of the deck condition is solely based on inspector's subjective interpretation of the sound produced by dragging a chain over the bridge deck. The use of GPR has the potential to greatly improve the quality of the inspections by collecting more reliable and less subjective information on the condition of bridge decks. Through the collection and analysis of data acquired from the GPR on a set of reinforced concrete decks, this research seeks to provide a better understanding of GPR technology, data acquisition, and training needs for adoption of GPR in bridge deck inspections in the state of New Mexico. With a better understanding of the technology, GPR can become and indispensable tool for more informed decisions for the allocation of funds for maintenance and improved asset management. This research improves implementation and provides effective economic methods to employ this technology to improve the inspection and maintenance of bridge infrastructure.
Author | : Timo Saarenketo |
Publisher | : |
Total Pages | : 56 |
Release | : 1994 |
Genre | : Ground penetrating radar |
ISBN | : |
This report will describe the various kinds of information that can be obtained from roads and highways with Ground Penetrating Radar. In the last 5 years, attention has focused on measuring the thickness of the asphalt surfacing layer on flexible pavements with air-launched horn antennas. Other antennas are available with substantially different depths of penetration, and for use in a wide range of other pavement applications. The purpose of this report is to describe the range of applications of GPR in pavement evaluation. Cases include subgrade investigations, bedrock evaluations, locating sinkholes, detecting frost damage, and identifying defects such as stripping or voids and monitoring crack growth within the pavement structure. The large variety of cases, conducted in Texas and Finland, illustrates the unique ability of GPR to rapidly evaluate subsurface conditions. The sinkhole detection study represents our initial effort to use low frequency deep penetrating radar on Texas pavements. A unique feature of this paper is the proposed classification of the frost susceptibility of subgrade soils by their measured dielectric constant and electrical conductivity.