"Concrete infrastructure of United States is aging and deteriorating. Accurate assessment the condition of concrete infrastructure is critical for its maintenance and rehabilitation. Stress-wave based methods, including ultrasonic surface wave (USW) and impact echo (IE), are becoming popular for characterizing defects and mechanical properties of concrete infrastructures. In this dissertation, a comprehensive literature review of seismic wave theory and common types of defects identified in concrete infrastructures, as well as stress-wave based methods used for concrete infrastructure monitoring and characterizing on a selected concrete bridge deck and two concrete pavement segments are present. The utility and reliability of both methods were carefully evaluated and validated based on the comparison analysis with other destructive or non-destructive testing (NDT) methods carried out in the field or laboratory for the same bridge decks and pavement segments, such as the concrete hydro-demolition, drilling, static modulus of elasticity of concrete specimens in compression and ground penetrating radar (GPR). Detailed investigation of the sensitivity and limitation of stress-wave based methods for different types of defects identified in concrete bridge decks and pavements has been performed and presented. The outcome of this study is to expand the knowledge of stress-wave based methods, to better understand their strengths and limitations, to evaluate the reliability and utility of both the USW and IE test results in characterizing and monitoring defects and mechanical properties of concrete infrastructures. The result of this study is most beneficial for transportation agencies and researchers to use stress-wave based methods properly and effectively for further feasibility studies or monitoring of concrete infrastructures"--Abstract, page iv.

An objective view of the relative advantages and limitations of the nondestructive testing and evaluation methods that are currently used in the inspection of bridge decks is presented and discussed. The three main nondestructive testing technologies that were evaluated are impact-echo, ground penetrating radar, and infrared thermography. Nondestructive testing and evaluation procedures, including methodology and equipment to evaluate concrete bridge decks with asphalt overlays, are also presented and discussed. Current results indicate that a combination of ground penetrating radar and infrared thermography would provide the best methodology for evaluating the structural integrity, e.g., delaminations, of concrete bridge decks with overlays. Furthermore, current results also indicate that the impact-echo method shows promising future development towards the nondestructive evaluation of bridge superstructures.

The definitive text in the field of Bridge Deck behaviour and analysis Bridge Deck Analysis is an essential reference for civil and structural engineers. It provides bridge designers with the knowledge to understand the behaviour of bridge decks, to be familiar with, and to understand the various numerical modelling techniques, to know which technique is most suited. The book covers the grillage analogy, dedicates a chapter to the modelling and analysis of integral bridge forms and also provides guidance of the application of the finite element method.

Civil engineers will value this resource that examines the tools and techniques used to estimate the in-place strength on concrete, permeation properties that relate to potential durability, and the methods used to assess the internal condition of concrete and the corrosion activity of steel reinforcement.

Proceedings of the International Workshop on Intelligent Structures, Taipei, Taiwan, 23-26 July 1990.

This book gives information on non destructive techniques for assessment of concrete structures. It synthesizes the best of international knowledge about what techniques can be used for assessing material properties (strength) and structural properties (geometry, defects...). It describes how the techniques can be used so as to answer a series of usual questions, highlighting their capabilities and limits, and providing advices for a better use of techniques. It also focuses on possible combinations of techniques so as to improve the assessment. It is based on many illustrative examples and give in each case references to standards and guidelines.

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.