The non-destructive evaluation (NDE) of civil infrastructure has been an active area of research in recent decades. The traditional inspection of civil infrastructure mostly relies on visual inspection using human inspectors. To facilitate this process, different sensors for data collection and techniques for data analyses have been used to effectively carry out this task in an automated fashion. This review-based study will examine some of the recent developments in the field of autonomous robotic platforms for NDE and the structural health monitoring (SHM) of bridges. Some of the salient features of this review-based study will be discussed in the light of the existing surveys and reviews that have been published in the recent past, which will enable the clarification regarding the novelty of the present review-based study. The review methodology will be discussed in sufficient depth, which will provide insights regarding some of the primary aspects of the review methodology followed by this review-based study. In order to provide an in-depth examination of the state-of-the-art, the current research will examine the three major research streams. The first stream relates to technological robotic platforms developed for NDE of bridges. The second stream of literature examines myriad sensors used for the development of robotic platforms for the NDE of bridges. The third stream of literature highlights different algorithms for the surface- and sub-surface-level analysis of bridges that have been developed by studies in the past. A number of challenges towards the development of robotic platforms have also been discussed.

Monitoring the condition of concrete bridge decks is essential because bridge decks are deteriorating faster than other bridge components. This study concentrated on bridge deck condition assessment using complementary nondestructive evaluation (NDE) techniques. The assessment had three main components: evaluation of the corrosive environment and corrosion processes, concrete degradation evaluation, and assessment with respect to deck delamination. Five NDE techniques were used: impact echo (IE) to detect and characterize delamination, ground-penetrating radar (GPR) to describe the corrosive environment, measurement of the concrete cover and description of its overall condition, half-cell potential (HCP) to assess corrosion activity, ultrasonic surface waves (USW) to describe concrete quality, and electrical resistivity (ER) to estimate corrosion rate. The ability of NDE methods to objectively characterize deterioration progression is illustrated by the results from four NDE surveys of a bridge in...

The main goals of this study are to provide an improved interpretation of flexural vibration modes of delaminations in concrete bridge decks detected using impact-echo testing, and to develop a simple two-dimensional (2D) visualization scheme to show the areal extent of likely delaminated regions. To achieve those goals, the study consisted of three main tasks. The first was development of an analytical formulation that relates the fundamental frequency of the response to the geometry of delamination in a concrete plate. The formulation was developed from the thin plate vibration theory and numerical model simulations. The second task was the development of a simple model for predicting dynamic behavior (flexural vibration) of delamination in concrete plates. Finally, in the third task, the validity of the proposed model was verified through a comparison of the results from an experimental study on a near-real-scale concrete bridge deck and the results reported in prior studies. As demonstrated, t...

The falling weight deflectometer (FWD) test is the most widely accepted and used technique for nondestructive evaluation of pavements. In this test, the pavement response to the impulse load of a falling weight is analyzed or back-calculated to evaluate the in situ pavement layer moduli. FWD back-calculation is mathematically an inverse problem that can be approached deterministically or probabilistically. In this paper, the probabilistic approach to FWD back-calculation is used as a tool to investigate the reliability of different dynamic and static back-calculation procedures. The probabilistic approach to FWD back-calculation, a relatively new approach, is initially introduced and a brief overview of its numerical implementation is presented. The approach is then applied to back-calculate moduli from a set of synthetic FWD data using different back-calculation procedures, such as static and dynamic deflection bowl or dynamic time history procedures. Based on the probabilistic solution for back-calculat...