This report summarizes efforts initiated and sponsored by the New Hampshire Department of Transportation related to location-specific predictions of corrosion and freeze/thaw induced deterioration on existing bridge decks scheduled for rehabilitation. In 1998, twin 842-ft (257-m) interstate bridges spanning the Connecticut River between Lebanon, New Hampshire and White River Junction, Vermont were surveyed using a combination of horn and ground-coupled antennas. These surveys, supplemented by an underside inspection and limited coring and chloride testing, were successfully used to estimate and locate repair areas prior to a deck rehabilitation project on the structures. In 1999, four structures located along I93 in Thornton-Woodstock, New Hampshire were surveyed without the use of supplemental, destructive testing or lane closures. Contour maps were produced on all structures, showing varying degrees of predicted deterioration.

The purpose of this study was to evaluate the reproducibility and accuracy of Ground Penetrating Radar (GPR) in locating delaminations and de-bonding in 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 infrared thermographic and GPR evaluation was conducted on the I-70 Polk-Quincy viaduct in 1993. A second GPR study was performed in 1997 to evaluate the condition of the bridge deck previous to removal of the existing asphalt overlay and high density concrete overlay and repair of the deteriorated deck. The results of the 1997 GPR study were compared to the results of the 1993 GPR study, the 1998 through 1999 chaining, actual repair areas and portions of the 1989 Geotechnical Unit bridge deck evaluation.

"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.

The traveling public has no patience for prolonged, high cost construction projects. This puts highway construction contractors under intense pressure to minimize traffic disruptions and construction cost. Actively promoted by the Federal Highway Administration, there are hundreds of accelerated bridge construction (ABC) construction programs in the United States, Europe and Japan. Accelerated Bridge Construction: Best Practices and Techniques provides a wide range of construction techniques, processes and technologies designed to maximize bridge construction or reconstruction operations while minimizing project delays and community disruption. - Describes design methods for accelerated bridge substructure construction; reducing foundation construction time and methods by using pile bents - Explains applications to steel bridges, temporary bridges in place of detours using quick erection and demolition - Covers design-build systems' boon to ABC; development of software; use of fiber reinforced polymer (FRP) - Includes applications to glulam and sawn lumber bridges, precast concrete bridges, precast joints details; use of lightweight aggregate concrete, aluminum and high-performance steel

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.

The Penetradar Integrated Radar Inspection System (IRIS) Ground Penetrating Radar (GPR) was selected by Dalhousie University DalTech as the most appropriate technology for assessing the condition of reinforced concrete bridge decks because of the ability of the system to penetrate through asphalt concrete overlays and Perform data collection at traffic speeds up to 75-80 km/hr. A collaborative research program was designed by Dalhousie University DalTech and the Nova Scotia Department of Transportation and Public Works to examine the accuracy and confidence with which GPR can be used to predict the quantity and location of laminations and concrete scaling On asphalt covered bridge decks. Seventy-two bridge decks were surveyed at traffic speeds using GPR for deterioration estimation. The GPR data was processed manually to determine areas of excess signal attenuation and areas of high concrete relative dielectric constant. Deterioration predictions made using GPR were also compared quantitatively and spatially to ground-truthing data obtained from nine bridge decks using the well-established chain drag and half-cell potential surveys after the asphalt was removed from each bridge deck just prior to repair.

The fourth Structural Materials Technology NDT Conference was held in Atlantic City, New Jersey, with over sixty speakers presenting on a wide variety of topics. The goal of this conference was to inform engineers and researchers of the new nondestructive testing/nondestructive evaluation (NDT/NDE) technologies and techniques available for use in transportation construction. The use of alternative materials is challenging NDT/NDE professionals to develop new methods or modify existing techniques to address quality control, quality assurance, and long-term monitoring of structures built or strengthened with these materials. One such alternative is fiber-reinforced polymer (FRP) products. This conference included papers on this topic and a panel discussion that focused on the future of NDT/NDE technologies for structures built or rehabilitated with FRP composites. These proceedings contain the 62 papers that were presented at the conference, arranged according to session number. An author index is included.

"TRB's National Cooperative Highway Research Program (NCHRP) Report 750, Volume 3: Strategic Issues Facing Transportation, Volume 3: Expediting Future Technologies for Enhancing Transportation System Performance presents the systematic technology reconnaissance, evaluation, and adoption methodology (STREAM). STREAM is a process that transportation agencies can use to identify, assess, shape, and adopt new and emerging technologies to help achieve long-term system performance objectives. The process reflects relevant trends in technologies and their applications and is designed to help transportation agencies anticipate, adapt to, and shape the future. NCHRP Report 750, Volume 3 is the third in a series of reports being produced by NCHRP Project 20-83: Long-Range Strategic Issues Facing the Transportation Industry. Major trends affecting the future of the United States and the world will dramatically reshape transportation priorities and needs. The American Association of State Highway and Transportation Officials (AASHTO) established the NCHRP Project 20-83 research series to examine global and domestic long-range strategic issues and their implications for state departments of transportation (DOTs); AASHTO's aim for the research series is to help prepare the DOTs for the challenges and benefits created by these trends." -- publisher's description

"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.