Intelligent Asphalt Compaction Analyzer

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Slide 1

Project Team: Haskell Lemon Construction Company, University of Oklahoma, Volvo Road Machinery, and EST Inc.

Award: $200,000

A video clip is available (.wmv, 10.2 mb)

Slide 2 – The Intelligent Asphalt Compaction Analyzer Is a Roller Mounted Device

Continuously senses the amplitude and frequency of vibrations of the compactor
Estimates, in real-time, the quality (compacted density, stiffness) during the construction of an asphalt pavement
Key features are the real-time monitoring of the compaction progress over the entire pavement

Slide 3 – Need

Ruts, potholes, cracks and other forms of defects reduce the useful life of a pavement
Improper or inadequate compaction is the most common cause of early degradation of asphalt pavements

Anticipated Advantages to Conventional Practice

Instantaneous and complete evaluation of the pavement being compacted
Higher efficiency and increased productivity
- Reduction in labor and fuel costs
- Reduction in the number of conventional spot tests
Higher adaptability of compaction process to suit thin/thick lifts, soft/stiff subgrades, etc.
Better quality resulting from uniform and optimum compaction

Slide 4 – Principle of Operation of the IACA

Conceptualized drawing of the operation of the IACA.

flow chart showing the operation of the IACA

Slide 5 – IACA User Display

screen shot of the IACA User Display. The display provides the current position of the roller, latitude and longitude, the temperature of the asphalt map, and the compacted density of the map.

The IACA display provides real-time information on the density and the mat temperature to the roller operator at each location on the pavement during each roller pass.

Slide 6 – IACA "As-Built" Density Map

Screen shot of the 'as-built' IACA density map. A photograph illustrates an area on the pavement that has inadequate compaction and the map illustrates how under compacted regions are displayed.

Concrete manhole cover

Density information from the final pass of the roller can be used to compile the final density of the entire pavement. The color-coded map (red is 90%, green is 92%, yellow is 94%,) portrays the uniformity of compaction that was achieved.
Areas in green indicate inadequate compaction or uncompacted areas resulting from relief features on the pavement surface).
Uneven compaction can be investigated to determine the cause. In this case, soft subgrade had resulted in uneven compaction.

Slide 7 – Comparison of IACA and Non-nuclear Density Measurements

Estimate density percentage over the length of the pavement.

The density estimates of the IACA are comparable to those obtained by point-wise measurements using a non-nuclear gauge.

The lower graph illustrates the comparison of the density measured from the roadway core and the estimated density.

The density estimates obtained using the IACA compare very favorably with density measured from roadway cores.