scholarly journals GPR Spectra for Monitoring Asphalt Pavements

2020 ◽  
Vol 12 (11) ◽  
pp. 1749 ◽  
Author(s):  
Josep Pedret Rodés ◽  
Adriana Martínez Reguero ◽  
Vega Pérez-Gracia
Keyword(s):  
Spectral Analysis ◽  
Ground Penetrating Radar ◽  
Wave Amplitude ◽  
Structural Condition ◽  
Asphalt Pavements ◽  
Preservation Conditions ◽  
Pavement Structures ◽  
The Fourier Transform ◽  
Ground Penetrating

Ground Penetrating Radar (GPR) is a prospecting method frequently used in monitoring asphalt pavements, especially as an optimal complement to the defection test that is commonly used for determining the structural condition of the pavements. Its application is supported by studies that demonstrate the existence of a relationship between the parameters determined in GPR data (usually travel time and wave amplitude) and the preservation conditions of the structure. However, the analysis of frequencies is rarely applied in pavement assessment. Nevertheless, spectral analysis is widespread in other fields such as medicine or dynamic analysis, being one the most common analytical methods in wave processing through use of the Fourier transform. Nevertheless, spectral analysis has not been thoroughly applied and evaluated in GPR surveys, specifically in the field of pavement structures. This work is focused on analyzing the behavior of the GPR data spectra as a consequence of different problems affecting the pavement. The study focuses on the determination of areas with failures in bituminous pavement structures. Results epitomize the sensitivity of frequencies to the materials and, in some cases, to the damage.

The New Swedish Cyprus Expedition 2010. Excavations at Dromolaxia Vizatzia/Hala Sultan Tekke. Preliminary results

2011 ◽  
Vol 4 ◽  
pp. 69-98 ◽  
Author(s):  
Peter M. Fischer ◽  
Patrik Klingborg ◽  
Fanny Kärfve ◽  
Fredrika Kärfve ◽  
C. Hagberg ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Main Task ◽  
Phase 2 ◽  
The North ◽  
12Th Century ◽  
Area 6 ◽  
Recent Phase ◽  
The Rich ◽  
Ground Penetrating

Determination of the complete occupational sequence of the site, including investigation of pre-12th century levels which were thoroughly studied by P. Åström since the 1970s, is the main task of the planned project. During the course of the expedition (NSCE11) in spring 2010 a ground-penetrating radar survey (GPR) was carried out at Dromolaxia Vizatzia/Hala Sultan Tekke in Area 6, leading to the discovery of a large Late Cypriote complex. The compound is bordered to the north by a substantial wall, against which nine rooms (so far) could be exposed. Two occupational phases have been verified but there are indications of a third. The suggested functions of the various structures of the most recent phase are: living, working, storage and administration spaces. The rich find contexts point to the production of textiles and metal objects, and the locally produced pottery is generally of a high quality. There are also many imports, mainly from the Mycenaean sphere of culture. The locally produced vessels from Phase 2 include the “Creature krater” which is a masterpiece of a high artistic standard. Another piece of elevated artistry is the piece of a “Warrior vase”.

scholarly journals Detection of Tree Roots in an Urban Area with the Use of Ground Penetrating Radar

2016 ◽  
Vol 17 (4) ◽  
pp. 362-370 ◽  
Author(s):  
Alexander Krainyukov ◽  
Igor Lyaksa
Keyword(s):  
Urban Area ◽  
Ground Penetrating Radar ◽  
Growth Direction ◽  
Technical Condition ◽  
Tree Roots ◽  
Secondary Processing ◽  
Non Invasive ◽  
Ground Penetrating ◽  
The Given

Abstract The paper is devoted to using ground penetrating radar (GPR) for the detection of tree roots in an urban area, since GPR allow detect the hidden objects in non invasive way. It is necessary exactly to know the growth direction, thickness and depth of the roots of the tree to confidently assert about the tree root influence on the technical condition of engineering objects and structures: of the buildings, of pavements, of roadway, of engineering communications and etc. The aim of the given research was experimentally to evaluation the possibilities of detection of tree roots in an urban area with the use of GPR on frequency 400 MHz and of algorithms of secondary processing of GPR signals. Results of interpretation of radar profile and evacuation of soil around tree show the possibility of detection of the tree roots and the determination of their parameters using one or two radar concentric profiles.

scholarly journals Lab Non Destructive Test to Analyze the Effect of Corrosion on Ground Penetrating Radar Scans

2019 ◽  
Vol 11 (23) ◽  
pp. 2814 ◽  
Author(s):  
Sossa ◽  
Pérez-Gracia ◽  
González-Drigo ◽  
Rasol
Keyword(s):  
Ground Penetrating Radar ◽  
Wave Amplitude ◽  
Metallic Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Accurate Analysis ◽  
Reflected Wave ◽  
Dense Grid ◽  
Ground Penetrating ◽  
Non Destructive

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.

scholarly journals Study on Wavelet Entropy for Airport Pavement Inspection using a Multi-Static GPR System

Geophysics ◽  
2021 ◽  
pp. 1-74
Author(s):  
Lilong Zou ◽  
Kazutaka Kikuta ◽  
Amir M. Alani ◽  
Motoyuki Sato
Keyword(s):  
Wavelet Transform ◽  
Ground Penetrating Radar ◽  
Large Area ◽  
New Approach ◽  
Wavelet Entropy ◽  
High Entropy ◽  
Airport Pavement ◽  
Base Experiment ◽  
Pavement Structures ◽  
Ground Penetrating

The multi-layer nature of airport pavement structures is susceptible to the generation of voids at the bonding parts of the structure, which is also called interlayer debonding. Observations have shown that the thickness of the resulting voids is usually at the scale of millimeters, which makes it difficult to inspect. The efficient and accurate characteristics of ground penetrating radar (GPR) make it suitable for large area inspections of airport pavement. In this study, a multi-static GPR system was used to inspect the interlayer debonding of a large area of an airport pavement. A special antenna arrangement can obtain common mid-point (CMP) gathers during a common offset survey. The presence of interlayer debonding affects the phase of the reflection signals, and the phase disturbance can be quantified by wavelet transform. Therefore, an advanced approach that uses the average entropy of the wavelet transform parameters in CMP gathers to detect the interlayer debonding of airport pavement is proposed. The results demonstrate that the regions with high entropy correspond to the regions where tiny voids exist. The new approach introduced in this study was then evaluated by a field-base experiment at an airport taxiway model. The results show that the proposed approach can detect interlayer debonding of the pavement model accurately and efficiently. The on-site coring results confirm the performance of the proposed approach.

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