scholarly journals Experimental study on ground penetrating radar in quality inspection of asphalt concrete impervious facing of pumped storage power station

2018 ◽  
Vol 423 ◽  
pp. 012020
Author(s):  
Xiulin Li ◽  
Jutao Hao ◽  
Zhengxing Wang
Keyword(s):  
Experimental Study ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Quality Inspection ◽  
Power Station ◽  
Pumped Storage ◽  
Ground Penetrating

scholarly journals A Method for Cavity Scale Estimation Based on Ground-Penetrating Radar (GPR) Explorations: An Experimental Study

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jeong-Jun Park ◽  
Yoonseok Chung ◽  
Gigwon Hong
Keyword(s):  
Experimental Study ◽  
Ground Penetrating Radar ◽  
Empirical Formula ◽  
Soil Depth ◽  
Additional Experiment ◽  
Cross Sectional ◽  
Scale Estimation ◽  
Cavity Collapse ◽  
Ground Penetrating

This study described the results of experiments comparing the cavity scales obtained from the GPR exploration with the direct excavation of the identified cavity scales. The first experiment was carried out on the actual roadway, and the additional experiment was carried out on the mock-up site to prevent the cavity collapse under the ground. It was confirmed that the soil depth of the predicted cavity and the identified cavity was similar, but the predicted cavity scales by GPR exploration overestimated the longitudinal and cross-sectional widths compared with the identified cavity scales. Based on the correlation between the cavity scales predicted by GPR exploration and the cavity scales identified in the mock-up test, an empirical formula for estimating the cavity scales was proposed.

scholarly journals Application Research of Ground-Penetrating Radar in the Quality Inspection of Concrete Anti-seepage Panels

2019 ◽  
Vol 136 ◽  
pp. 04032
Author(s):  
Meng Li ◽  
Changde Ren ◽  
Lei Zhao ◽  
Shijiao Luo
Keyword(s):  
Ground Penetrating Radar ◽  
Rock Foundation ◽  
Quality Inspection ◽  
Local Instability ◽  
Application Research ◽  
Safe Operation ◽  
Ground Penetrating

If the sand-free cushion of concrete anti-seepage panels of reservoir is void, it will cause local instability or even crack and collapse of the panel, which will lead to large leakage of reservoir and affect the safe operation of the project. In this paper, the ground-penetrating radar (GPR) method is used to scan the concrete panel. The results show that the quality of the panel is good overall, the distribution of rebar is uniform, and the contact between the panel and the sand-free cushion is dense. Some panels have internal voids and the contact between the cushion and the rock foundation is not dense, while no obvious hollowing is found in the sand-free cushion.

A Kind of Auxiliary System Affiliated Ground Penetrating Radar Based on Road Disease Detection

2014 ◽  
Vol 522-524 ◽  
pp. 1182-1186 ◽  
Author(s):  
Yun Hai Xia ◽  
Feng Yang ◽  
Xian Lei Xu
Keyword(s):  
Ground Penetrating Radar ◽  
Auxiliary System ◽  
Disease Detection ◽  
Quality Inspection ◽  
Test Results ◽  
Precise Location ◽  
Ground Penetrating ◽  
Actual Test

In the application of ground penetrating radar (GPR) to detect roadbed diseases, this paper designs a kind of auxiliary system for GPR to solve the problems ,such as how to obtain precise location of the diseases and how to explain the causes of the roadbed disease more reasonably. Combined with the actual test results, this paper discusses the feasibility and superiority of the auxiliary system in quality inspection of highway roadbed.

scholarly journals Effect of Moisture Content on Calculated Dielectric Properties of Asphalt Concrete Pavements from Ground-Penetrating Radar Measurements

2021 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Qingqing Cao ◽  
Imad L. Al-Qadi
Keyword(s):  
Dielectric Properties ◽  
Numerical Model ◽  
Moisture Content ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Concrete Pavements ◽  
Proposed Model ◽  
Moisture Variation ◽  
Ground Penetrating ◽  
Non Destructive

Moisture presence in asphalt concrete (AC) pavement is a major cause of damage to the pavement. In recent decades, an increasing need exists for non-destructive detection and monitoring of the moisture content in AC pavement. This paper provides a simulated approach to quantify the effect of internal moisture content on AC pavement dielectric properties using ground-penetrating radar (GPR). A heterogeneous numerical model was developed to simulate AC pavement with internal moisture at various saturation levels. The numerical model was validated using GPR surveys on cold-in-place recycling treated pavements. An empirical formula was derived from the simulation to correlate the dielectric constant with the moisture content for non-dry AC pavement. The results validated the proposed model and, hence, demonstrated the ability of GPR to monitor moisture variation in AC pavements.

Real-Time Monitoring of Asphalt Concrete Pavement Density during Construction using Ground Penetrating Radar: Theory to Practice

2019 ◽  
Vol 2673 (5) ◽  
pp. 329-338 ◽  
Author(s):  
Siqi Wang ◽  
Shan Zhao ◽  
Imad L. Al-Qadi
Keyword(s):  
Real Time ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Linear Optimization ◽  
Field Tests ◽  
The United States ◽  
Construction Process ◽  
Pavement Construction ◽  
Ground Penetrating ◽  
Time Density

Accurate real-time density monitoring is crucial in quality control and quality assurance during the asphalt concrete (AC) pavement construction process. Ground penetrating radar (GPR) technology has shown great potential in the continuous real-time density prediction of AC pavement. However, it is not accepted as a routine method by transportation agencies in the United States due to the lack of validation under field testing conditions. In this study, three field tests were performed using GPR to estimate AC pavement density. The Al-Qadi-Lahouar-Leng model was used to predict the density from GPR signals. The reference scan method was used to remove the effect of surface moisture during construction. The gradient descent-based non-linear optimization method was used to reconstruct the overlapped GPR signals result from the use of thin AC overlay, which has been widely implemented as an AC pavement rehabilitation technique. Digital filtering and other signal processing methods were used to de-noise the signal. GPR results using the proposed methods were compared with field core data and nuclear gauge results. The results show that the proposed methods were effective in estimating in-situ AC pavement density using GPR. Continuous density estimation by installing GPR on the roller is suggested to provide real-time compaction monitoring during the AC pavement construction process.

Experimental Research on Dielectric Constant Model for Asphalt Concrete Material

2011 ◽  
Vol 250-253 ◽  
pp. 2760-2764
Author(s):  
Bei Zhang ◽  
Yan Hui Zhong ◽  
Hua Xue Liu ◽  
Fu Ming Wang
Keyword(s):  
Dielectric Constant ◽  
Experimental Research ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Concrete Material ◽  
The Real ◽  
Applied Technology ◽  
New Models ◽  
Pavement Structures ◽  
Ground Penetrating

Aiming at the problems of the applied technology of ground penetrating radar(GPR), the rationality and applicability of some common existed dielectric constant models to asphalt concrete material are verified and modified based on experiment, and then the new dielectric constant model models suitable for asphalt concrete material are established. The new models are applied to the real project, the results show that the new models can explain the characteristics of asphalt concrete material more accurately, and the calculated error of the compaction of pavement structures based on the modified models is significantly reduced compared to that based on the existed models.

Non-Destructive Detection of Asphalt Concrete Stripping Damage using Ground Penetrating Radar

2021 ◽  
pp. 036119812110141
Author(s):  
Ye Ma ◽  
Mostafa A. Elseifi ◽  
Nirmal Dhakal ◽  
Mohammad Z. Bashar ◽  
Zhongjie Zhang
Keyword(s):  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Field Data ◽  
Visual Inspection ◽  
Asphalt Pavements ◽  
Reflected Waves ◽  
Ground Penetrating ◽  
The Relationship ◽  
Non Destructive ◽  
Difference Time

Ground penetrating radar (GPR) is a non-destructive evaluation technique, which has been applied to assess as-built pavement conditions and to evaluate damage and deterioration that develop over time. The objective of this study was to develop a methodology that uses GPR to detect moisture-related stripping damage in asphalt pavements. To achieve this objective, A Finite-Difference Time-Domain based simulation program was used to study the propagation of GPR signals in a stripped pavement. Field test data including GPR scans and visual inspection of cores of 202 pavement sections were used to study the relationship between GPR traces and asphalt concrete (AC) stripping damage. Based on this analysis, a novel GPR-based indicator, known as the accumulating in-layer peaks (AIP), was introduced to detect stripping damage in asphalt pavements. Field data and pavement cores were used to validate the proposed indicator and to evaluate its effectiveness in detecting the presence, extent, and severity of stripping in in-service pavement sections. Based on the results of the study, it was found that the presence of a void in the middle of the AC layer resulted in positive peaks in the reflected waves as indicated by the simulation of GPR signals. In addition, detected intermediate wave peaks between the surface and the interface between the AC and base layers on the GPR traces were associated with stripping damage in the AC layer. The AIP predicted accuracies for stripped and non-stripped sections were 80% and 96%, respectively, indicating its effectiveness in detecting stripping damage in flexible pavements.

Signal Stability and the Height-Correction Method for Ground-Penetrating Radar In Situ Asphalt Concrete Density Prediction

2021 ◽  
pp. 036119812110045
Author(s):  
Qingqing Cao ◽  
Imad L. Al-Qadi
Keyword(s):  
Adaptive Filter ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Correction Method ◽  
Least Square ◽  
Least Mean Square ◽  
Signal Stability ◽  
Density Prediction ◽  
Ground Penetrating ◽  
The Impact

Ground-penetrating radar (GPR) has shown great potential for asphalt concrete density prediction used in quality control and quality assurance. One challenge of continuous GPR measurements is that the measured dielectric constant could be affected by signal stability and antenna height. This would jeopardize the accuracy of the asphalt concrete density prediction along the pavement. In this study, signal instability and shifting antenna height during continuous real-time GPR measurements were identified as main sources of error. After using a bandpass filter to preprocess the signal, a least-square adaptive filter, using gradient descent and least mean square methods, was developed to reconstruct the received signal to improve its stability. In addition, simulations were performed to evaluate the impact of geometric spreading caused by shifting antenna height during testing. A height correction was developed using a power model to correct the height-change impact. The proposed filter and height-correction method were assessed using static and dynamic tests. The least-square adaptive filter improved signal stability by 50% and the height-correction method removed the effect of shifting antenna height almost entirely.

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