Asphalt Dielectric Measurement Accuracy Using Surface Temperature
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Solution Overview
Problem
Ground-penetrating radar (GPR) measurements of asphalt compaction are inaccurate due to the presence of water on the asphalt surface, which affects the reflection of radar waves and results in non-useful measurements, limiting its deployment on rollers for real-time feedback during the compaction process.
Innovation Solution
A method that uses a combination of temperature sensing, such as with an infrared camera or wire comb, and GPR to detect the presence of water on the asphalt surface, allowing for the adjustment of dielectric measurements to compensate for the water's effect, thereby providing accurate compaction data despite surface moisture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If GPR is used to measure asphalt compaction in real-time, then productivity and feedback speed improve, but measurement precision deteriorates due to water on the surface
Solution Approach 1:
The patent introduces temperature as an intermediary parameter to detect the presence of water on the asphalt surface. By measuring temperature anomalies (water cools the surface), the system identifies when water is present and applies correction factors to the dielectric measurements, thereby maintaining measurement precision while enabling real-time monitoring
Solution Approach 2:
The patent changes the measurement parameters by incorporating temperature data alongside dielectric measurements. By monitoring temperature variations and using them to adjust the dielectric measurement interpretation, the system compensates for water interference and maintains accurate compaction measurements in real-time
2Measurement precision
If temperature measurement is added to detect water presence, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent makes the measurement system multi-functional by using the temperature sensor not only to detect water presence but also to provide information about asphalt compaction quality directly. This universal approach allows one additional sensor to serve multiple purposes, reducing the need for separate dedicated components and limiting the increase in overall system complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and real-time determination of asphalt compaction levels by correcting dielectric measurements affected by surface water, making GPR systems viable for use on rollers during the compaction process, ensuring optimal compaction and extending the lifespan of asphalt surfaces.
Implementation Method 1
GPR, or ground-penetrating RADAR (where RADAR is 'RAdio Detection And Ranging)'
Implementation Method 2
A dielectric, or measure of conductivity, for the asphalt is determined based on the received response
Implementation Method 3
a temperature of the asphalt is measured with a temperature measuring device such as an infrared camera
Data Source
AI summary
Dielectric values of cooling asphalt are obtained despite the presence of water on the surface thereof which effects the measured dielectric. The temperature of the surface of the asphalt is measured simultaneous or contemporaneous to a measurement of the dielectric, the former by way of an infrared camera and the latter by way of a ground penetrating radar transceiver, in embodiments of the disclosed technology. The ground penetrating radar moves with a roller on the surface of the asphalt and the camera can also move with and be mounted on the housing or can be separate, such as in a drone flying at a higher altitude than the asphalt and housing. Using a reference measurement for the mix design of the asphalt without water or with varying degrees of water, the changed dielectric due to the presence of water can be corrected to reveal the dielectric of the asphalt alone.