Government reports and published research have flagged and brought to public attention the deteriorating condition of a large percentage of bridges in Canada and the United States. Inspection and rehabilitation programs are being implemented to monitor and maintain deteriorated bridge infrastructure. Current practices of bridge inspection and condition assessment rely heavily on visual inspection, limited basic testing such as hammer sounding and chain dragging, and the use of Non-Destructive Testing on ad-hoc basis. These methods suffer from several limitations including subjectivity and uncertainty of visual inspection process, as well as traffic disruption resulting from lane closure during inspection. This research aimed to study, evaluate, and experiment with the use of remote sensing technologies in bridge inspection to minimize drawbacks of current practice. To achieve this objective, two models are developed in this research. The first is a comparative study of remote sensing technologies for concrete bridge condition assessment that provides a systematic approach of selecting most suitable technologies for use in condition assessment. Seven remote sensing technologies are examined in this model. It recommends technologies to be implemented based on a set of flexible multi-attributed criteria. The model provides flexibility to select specific set of these criteria and to define their weights based on user preferences and project objectives. The second model proposes a hybrid system of remote sensing technologies to augment current practice in bridge inspection and eliminate some limitations such as minimizing traffic disruption while performing bridge inspection and enhancing inspection data analysis and visualization. The hybrid system integrates the use of thermal Infrared (IR) and Ground Penetrating Radar (GPR). These technologies have the ability of acquiring data from a distance which minimizes traffic disruption. Results obtained from IR and GPR are in the form of maps of the detected defects on the concrete bridge deck. These maps are used as input in ArcGIS for better representation, visualization, and reporting of the defects and their extents. The hybrid system was examined in a case study of a concrete bridge deck in the city of Laval, Montreal, Quebec, Canada. The results are compared to those obtained using hammer sound test for validation.

Reinforced concrete bridge decks are high performance structural elements that must survive decades of harsh mechanical and environmental loads. The structural health monitoring of bridges is a primary enabler of safe and cost-effective performance, relying on frequent inspections and repairs as needed. The undersides of concrete bridge decks are oft-overlooked areas of inspection, owing to a hard to reach and difficult location to access. Exacerbating factors to the degradation of concrete bridge decks are the freeze-thaw cycle and salt water related corrosion common in the world's Northern climates. As concrete weathers, it decays. Corrosion induced cracking and delamination are primary damage modes.Moreover, budgets are forced to contend with the seasonal roadway damage from frost-heaves and snowplows, which can lead to delays in the inspection and repair of the undersides of bridge decks. Years of neglect have led to a growing need for assessment and repair. Despite this need, the inspection of the undersides of bridge decks is laborious and costly, requiring the shutdown of roadways, the use of specialized equipment, and an above-average operator risk. Ironically, while the cost of early detection of subsurface cracks is prohibitive, the cost of repair rises when early detection is not feasible. The key is knowing where the defects are, and how extensive the damage. In recent decades, numerous methodologies for concrete crack and delamination detection have become commercially available, however the undersides of bridge decks continue to pose a challenge. Often, detection is not financially feasible until cracks have reached the surface, or concrete has fallen off the structure. Reports of vehicles struck by falling concrete are not uncommon, demonstrating the need for an affordable robust early detection methodology for failing concrete. In this thesis, a technology down-select is performed to determine the optimal solution to detecting subsurface delaminations in the underside of concrete bridge decks. The solution alighted upon is an active acoustic sensor (AAS) mounted on an unmanned arial vehicle (UAV) platform to tap and listen to the underside of bridge decks. A mechanical tapping mechanism is developed to acquire the tap data remotely using a high frequency acoustic sensor. Embedded void concrete samples of 12" and 24" form factors are used as test beds in laboratory conditions. Subsequent post-processing using the Fast Fourier Transform (FFT) and the Welch Power Spectral Density (PSD) and Hilbert-Huang Transform (HHT) are used to differentiate a solid slab from one with a void. This research has shown the methodology to be feasible, and has laid the groundwork for additional effort to refine the design and bring it to a readiness level robust enough for in-situ testing in the field.

This book gathers the latest advances and innovations in the field of quality control and improvement of bridges and structures, as presented by international researchers and engineers at the 1st Conference of the European Association on Quality Control of Bridges and Structures (EUROSTRUCT 2021), held in Padua, Italy on August 29 – September 1, 2021. Contributions include a wide range of topics such as testing and advanced diagnostic techniques for damage detection; SHM and AI, IoT and machine learning for data analysis of bridges and structures; fiberoptics and smart sensors for long-term SHM; structural reliability, risk, robustness, redundancy and resilience for bridges; corrosion models, fatigue analysis and impact of hazards on infrastructure components; bridge and asset management systems, and decision-making models; Life-Cycle Analysis, retrofit and service-life extension, risk management protocols; quality control plans, sustainability and green materials.

Sensor Technologies for Civil Infrastructure, Volume 2: Applications in Structural Health Monitoring, Second Edition, provides an overview of sensor applications and a new section on future and emerging technologies. Part one is made up of case studies in assessing and monitoring specific structures such as bridges, towers, buildings, dams, tunnels, pipelines, and roads. The new edition also includes sensing solutions for assessing and monitoring of naval systems. Part two reviews emerging technologies for sensing and data analysis including diagnostic solutions for assessing and monitoring sensors, unmanned aerial systems, and UAV application in post-hazard event reconnaissance and site assessment. Includes case studies in assessing structures such as bridges, buildings, super-tall towers, dams, tunnels, wind turbines, railroad tracks, nuclear power plants, offshore structures, naval systems, levees, and pipelines Reviews future and emerging technologies and techniques including unmanned aerial systems, LIDAR, and ultrasonic and infrared sensing Describes latest emerging techniques in data analysis such as diagnostic solutions for assessing and monitoring sensors and big data analysis