Evaluating the Quality of Curing Applications on Concrete Pavements with Ground-Penetrating Radar

2021 ◽  
pp. 036119812199636
Author(s):  
Alireza Joshaghani ◽  
Dan G. Zollinger
Keyword(s):  
Ground Penetrating Radar ◽  
Weather Conditions ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Dielectric Measurements ◽  
Field Investigations ◽  
Pavement Construction ◽  
Ground Penetrating ◽  
Curing Compound

The management of concrete pavement curing must take several factors into account, such as the type of curing compound, the rate of the curing application, the uniformity of the curing application, the timing of the application, and the ambient weather conditions. This paper aims to elucidate a new curing application protocol for new concrete pavement construction and introduce a technique to address curing viability. Data for the development of the protocol were obtained from field investigations involving a series of test sections associated with concrete paving projects in: Victoria, TX; Itasca, IL; and Jacksonville, FL. For this undertaking, ground-penetrating radar technology was used to evaluate the efficacy of curing in relation to repeatability and uniformity. Statistical analysis was used to validate the utility of using dielectric measurements to qualify the curing quality. The rate of decrease in the dielectric constant was the critical parameter for evaluating a curing practice. Also, based on the coefficient of variation of data collection, the repeatability of data was acceptable. Finally, as a new method for checking the uniformity of curing applications, percent within limits (PWL) was implemented. Based on the PWL results, the hand-spraying led to a higher degree of non-uniformity in the spraying patterns compared with the spraying machine.

scholarly journals Ground penetrating radar detection of subsnow slush on ice-covered lakes in interior Alaska

2012 ◽  
Vol 6 (6) ◽  
pp. 1435-1443 ◽  
Author(s):  
A. Gusmeroli ◽  
G. Grosse
Keyword(s):  
Ground Penetrating Radar ◽  
Geophysical Methods ◽  
Arctic Region ◽  
Water Harvesting ◽  
Lake Ice ◽  
Wet Snow ◽  
Dry Conditions ◽  
Ground Penetrating ◽  
Ice Water

Abstract. Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. The frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe traveling condition onto lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow slush is almost impossible our understanding on overflow processes is still very limited and geophysical methods that allow water and slush detection are desirable. In this study we demonstrate that a commercially available, lightweight 1 GHz, ground penetrating radar system can detect and map extent and intensity of overflow. The strength of radar reflections from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of overflow also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by overflow.

Measurement of Bulk Electrical Properties Using GPR with a Variable Reflector

2018 ◽  
Vol 23 (4) ◽  
pp. 489-496
Author(s):  
J. David Redman ◽  
A. Peter Annan ◽  
Nectaria Diamanti
Keyword(s):  
Electrical Properties ◽  
Moisture Content ◽  
Ground Penetrating Radar ◽  
Arrival Time ◽  
Wood Chip ◽  
Direct Wave ◽  
Trace Data ◽  
Ground Penetrating ◽  
Prototype Instrument

Bulk electrical properties of media are important inherently for ground penetrating radar (GPR) applications and for providing a means to determine indirectly other physical properties such as moisture content. We have developed a reflector whose reflectivity can be controlled electronically. This variable reflector controlled by a GPR provides an effective method to measure bulk electrical properties of media. For sample measurements, the GPR is placed on one side of a sample and the variable reflector on the opposite side. GPR trace data are then acquired with the reflector in an on-state and in the off-state. By differencing these measurements, we improve the ability to detect the specific reflection event from the variable reflector. This process removes both the direct wave and clutter from the trace data, improving the quality of the refection event and our ability to accurately pick its arrival time and amplitude. We describe the variable reflector, a prototype instrument based on the reflector and numerical modeling performed to understand its response. We also show the results of testing applications to the measurement of wood chip moisture content and monitoring of the electrical properties of concrete during the curing process.

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.

scholarly journals Ground penetrating radar detection of subsnow liquid overflow on ice-covered lakes in interior Alaska

2012 ◽  
Vol 6 (4) ◽  
pp. 3079-3099 ◽  
Author(s):  
A. Gusmeroli ◽  
G. Grosse
Keyword(s):  
Ground Penetrating Radar ◽  
Geophysical Methods ◽  
Arctic Region ◽  
Lake Ice ◽  
Wet Snow ◽  
Dry Conditions ◽  
Ground Penetrating ◽  
Ice Water ◽  
Safe Access

Abstract. Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. This frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe access to these lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow liquid overflow (SLO) is almost impossible our understanding on SLO processes is still very limited and geophysical methods that allow SLO detection are desirable. In this study we demonstrate that a commercially available, lightweight 1GHz, ground penetrating radar system can detect and map extent and intensity of SLO. Radar returns from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of SLO also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by SLO.

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.

scholarly journals Subsoil Recognition for Road Investment Supported by the Integration of Geodetic and GPR Data in the Form of a Point Cloud

2021 ◽  
Vol 13 (19) ◽  
pp. 3886 ◽  
Author(s):  
Łukasz Ortyl ◽  
Marta Gabryś
Keyword(s):  
Ground Penetrating Radar ◽  
Point Cloud ◽  
Geophysical Methods ◽  
Road Construction ◽  
Spatial Visualization ◽  
Design Stage ◽  
Quality Of Results ◽  
Structure Surface ◽  
Ground Penetrating

During road construction investments, the key issue affecting the structure’s safety is accurate subsoil recognition. Identifying subsoil variability zones or natural voids can be performed using geophysical methods, and ground-penetrating radar (GPR) is recommended for this task as it identifies the location and spatial range karst formations. This paper describes the methodology of acquisition and processing of GPR data for ground recognition for road investment. Additional subsoil research was performed after karst phenomena were identified in the investment area, formations not revealed by geological recognition from earlier studies during the pre-design stage. Mala Ramac CU II radar with a 250 MHz antenna and a Leica DS2000 with 250 and 700 MHz antennas with real-time geopositioning were used to obtain the data. Regarding GPR data postprocessing, we present a method of converting spatial visualization into a point cloud that allows for GPR and geodetic data integration and confrontation. This approach enabled us to determine the locations of control trenches, the results of which were used for material validation, which is necessary to improve the reliability of subsoil recognition. The results showed a high correlation between the recorded GPR signals and the subsoil structure. Additionally, differences in the quality of results for measurements conducted before laying supporting layers with slag and on the completed road structure surface are illustrated.

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.

Has Diamond Grinding Been A Cost Effective Pavement Preservation Treatment In Australia?

2021 ◽  
Author(s):  
George Vorobieff
Keyword(s):  
Concrete Pavement ◽  
Pavement Design ◽  
Ride Quality ◽  
Skid Resistance ◽  
Concrete Pavements ◽  
Pavement Preservation ◽  
Diamond Grinding ◽  
Grinding Machines ◽  
Asset Managers

Australia introduced conventional longitudinal diamond grinding of highway concrete pavements in 2009 with the purchase of two "4‐foot" highway grinding machines by two contractors. The availability of these machines in Australia has enabled contractors to improve ride quality of new pavements, rather than accept a deduction to the tendered rate for the supply and placement of concrete pavement. Grinding of new concrete base is permitted up to an IRI of 3.5 m/km, thereby reducing the need to remove and replace concrete pavement which met the specified thickness, strength and density, but not ride quality. More importantly, with the introduction of the grinding machines, asset managers have the opportunity to use diamond grinding to treat existing concrete pavements that have a rough ride, or when the textured surface no longer meets specified levels for skid resistance. Although the primary use of diamond grinding was to improve ride quality of new and existing concrete pavements, it has also been used to: treat stepping across transverse contraction joints in PCP, improve skid resistance at roundabouts, improve both ride quality and texture for JRCP pavements (greater than 40 years of age) with a thin wearing course and spalling in the asphalt at transverse joints. The above treatments to concrete pavement allow asset preservation and avoid high reconstruction costs. The Austroads concrete pavement design procedure is based on the PCA design method and road smoothness is not a design parameter, unlike the USA approach to concrete pavement design where ride quality is a design input. There is still much work to be done to convince asset managers in Australia that the removal of the high areas of a concrete pavement to smooth the surface, reduces the dynamic wheel loading and minimises accumulated fatigue stress in the concrete. This paper reviews the last 10 years of diamond grinding projects and the success of this pavement preservation treatment for new and existing urban and rural concrete pavements in Australia. Recommendations to reduce the cost of diamond grinding concrete pavements and extend the use of this treatment are also provided.

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