scholarly journals Editorial for the Special Issue “Advanced Techniques for Ground Penetrating Radar Imaging”

2021 ◽  
Vol 13 (18) ◽  
pp. 3696
Author(s):  
Yuri Álvarez López ◽  
María García-Fernández

Ground Penetrating Radar (GPR) has become one of the key technologies in subsurface sensing and, in general, in Non-Destructive Testing (NDT), since it is able to detect both metallic and nonmetallic targets [...]

2019 ◽  
Vol 11 (23) ◽  
pp. 2814 ◽  
Author(s):  
Sossa ◽  
Pérez-Gracia ◽  
González-Drigo ◽  
Rasol

Corrosion is a significant damage in many reinforced concrete structures, mainly in coastal areas. The oxidation of embedded iron or steel elements degrades rebar, producing a porous layer not adhered to the metallic surface. This process could completely destroy rebar. In addition, the concrete around the metallic targets is also damaged, and a dense grid of fissures appears around the oxidized elements. The evaluation of corrosion is difficult in early stages, because damage is usually hidden. Non-destructive testing measurements, based on non-destructive testing (NDT) electric and magnetic surveys, could detect damage as consequence of corrosion. The work presented in this paper is based in several laboratory tests, which are centered in defining the effect of different corrosion stage on ground penetrating radar (GPR) signals. The analysis focuses on the evaluation of the reflected wave amplitude and its behavior. The results indicated that an accurate analysis of amplitude decay and intensity could most likely reveal an approach to the state of degradation of the embedded metallic targets because GPR images exhibit characteristics that depend on the effects of the oxidized rebar and the damaged concrete. These characteristics could be detected and measured in some cases. One important feature is referred to as the reflected wave amplitude. In the case of corroded targets, this amplitude is lower than in the case of reflection on non-oxidized surfaces. Additionally, in some cases, a blurred image appears related to high corrosion. The results of the tests highlight the higher amplitude decay of the cases of specimens with corroded elements.


Author(s):  
J. Yang ◽  
M. Fu

Due to the use of wood and other non-permanent materials, traditional Chinese architecture is one of the most fragile constructions in various heritage objects today. With the increasing emphasis on the protection of cultural relics, the repair project of wooden structure has become more and more important. There are various kinds of destructions, which pose a hidden danger to the overall safety of the ancient buildings, caused not only by time and nature, but also by improper repairs in history or nowadays. Today, the use of digital technology is a basic requirement in the conservation of cultural heritage. Detection technology, especially non-destructive testing technology, could provide more accurate records in capturing detailed physical characteristics of structures such as geometric deformation and invisible damage, as well as prevent a man-made destruction in the process of repair project. This paper aims to interpret with a typical example, Ancestral Temple in Mukden Palace, along with a discussion of how to use the non-destructive testing technology with ground penetrating radar, stress wave, resistograph and so on, in addition to find an appropriate protection method in repair project of traditional Chinese wooden architecture.


2021 ◽  
Vol 13 (4) ◽  
pp. 672
Author(s):  
Mercedes Solla ◽  
Vega Pérez-Gracia ◽  
Simona Fontul

The non-destructive testing and diagnosis of transport infrastructures is essential because of the need to protect these facilities for mobility, and for economic and social development. The effective and timely assessment of structural health conditions becomes crucial in order to assure the safety of the transportation system and time saver protocols, as well as to reduce excessive repair and maintenance costs. Ground penetrating radar (GPR) is one of the most recommended non-destructive methods for routine subsurface inspections. This paper focuses on the on-site use of GPR applied to transport infrastructures, namely pavements, railways, retaining walls, bridges and tunnels. The methodologies, advantages and disadvantages, along with up-to-date research results on GPR in infrastructure inspection are presented herein. Hence, through the review of the published literature, the potential of using GPR is demonstrated, while the main limitations of the method are discussed and some practical recommendations are made.


2020 ◽  
Author(s):  
Chiara Ferrante ◽  
Luca Bianchini Ciampoli ◽  
Fabio Tosti ◽  
Amir Morteza Alani ◽  
Andrea Benedetto

<p>Most of the damage in road-flexible pavements occur where stiffness of the asphalt and load-bearing layers is low. To this extent, an effective assessment of the strength and deformation properties of these layers can help to identify the most critical sections [1].</p><p>This work proposes an experimental-based model [2] for the assessment of the bearing capacity of road-flexible pavements using ground-penetrating radar (GPR – 2 GHz horn antenna) and the Curviameter [3] non-destructive testing (NDT) methods. It is known that the identification of early decay and loss of bearing capacity is a major challenge for effective maintenance of roads and the implementation of pavement management systems (PMSs). To this effect, a time-efficient methodology based on a quantitative modelling of road bearing capacity is developed in this study. The viability of using a GPR system in combination with the Curviameter NDT equipment is also proven.</p><p>The research is supported by the Italian Ministry of Education, University and Research under the National Project “Extended resilience analysis of transport networks (EXTRA TN): Towards a simultaneously space, aerial and ground sensed infrastructure for risks prevention”, PRIN 2017, Prot. 20179BP4SM</p><p> </p><p>[1] Frangopol, D.M.; Liu, M. Maintenance and management of civil infrastructure based on condition, safety, optimization, and life-cycle cost. Infrastruct. Eng. 2007, 1, 29–41.</p><p>[2] Tosti, C. L. Bianchini, F. D'Amico, A. M. Alani and A. Benedetto, “An experimental-based model for the assessment of the mechanical properties of road pavements using ground-penetrating radar,” Construction and Building Materials, vol. 165, pp. 966-974, 2018.</p><p>[3] M. Simonin, J.L. Geffard, P. Hornych, Performance of deflection measurement equipment and data interpretation in France, International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) September 15–17, 2015, Berlin, Germany.</p>


Author(s):  
BASO MARUDDANI ◽  
EFRI SANDI EFRI SANDI ◽  
MUHAMMAD FADHIL NAUFAL SALAM

ABSTRAKAntena Vivaldi merupakan salah satu jenis antena yang diimplementasikan pada radar penembus permukaan (Ground Penetrating Radar, GPR). GPR adalah salah satu metode non-destructive testing yang biasa digunakan untuk mengetahui kondisi beton/jalan raya. Penelitian ini merancang sebuah antena Vivaldi untuk digunakan pada GPR dengan frekuensi kerja 1 GHz – 2 GHz. Metode yang digunakan untuk merancang dan mengoptimasi antena Vivaldi adalah dengan mengubah beberapa parameter untuk mencapai spesifikasi yang diinginkan. Parameter tersebut antara lain lebar antena, panjang antena dan tapered slot. Optimasi yang dilakukan tetap memperhatikan pola radiasi antena agar tetap terarah. Hasil penelitian ini menghasilkan antena Vivaldi dengan dimensi 350x300 mm dengan return loss di bawah -10 dB pada rentang frekuensi 1 GHz – 2 GHz. Hasil penelitian juga menunjukkan bahwa perubahan nilai parameter lebar antena dan tapered slot menggeser frekuensi kerja antena secara signifikan.Kata kunci: Ground Penetrating Radar, Vivaldi, return loss, parameter antena ABSTRACTThe Vivaldi antenna is one type of antenna that is implemented on Ground Penetrating Radar (GPR). GPR is one of the non-destructive testing methods commonly used to determine the condition of concrete / highway. This studyaim to design a Vivaldi antenna to be used on GPR with a working frequency of 1 GHz - 2 GHz. The method that used to design and optimize Vivaldi antennas is by changing several parameters to achieve the desired specifications. These parameters include antenna width, antenna length and tapered slot. Optimization carried out still observes the radiation pattern of the antenna to keep it directed. The results showed that 350 x 300 mm antennas with return loss below -10 dB in the frequency range of 1 GHz - 2 GHz. The results also show that changes in the parameter width of the antenna and tapered slots shift the antenna working frequency significantly.Keywords: Ground Penetrating Radar, Vivaldi, return loss, antenna parameter


2013 ◽  
Vol 569-570 ◽  
pp. 1210-1217
Author(s):  
Gonzalo Safont ◽  
Addisson Salazar ◽  
Luis Vergara ◽  
Antonio Vidal ◽  
Alberto Gonzalez

This paper presents a method for assessment of historic structures based on the fusion of data from ground-penetrating radar (GPR), ultrasound, and impact-echo testing. The method consists of the following steps: measuring, feature extraction, fusion, representation, and evaluation. The employed techniques for an application in scale models of historical walls are described. Thus, experimental deployment; signal feature processing; fusion operators (including order statistics digital filters); 2D non-destructive testing images, and figures of merits of the fused results are explained in detail. The deformation of different imperfections in the material structure related to the application of weight load increments applied on the wall is analyzed by using different kinds of fusion configurations.


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