Volume 28, Issue 6 (November 2000)
Evaluation of Density Gradients in Loaded Wheel Tester Samples
The Asphalt Pavement Analyzer is a tool used to estimate the rutting potential of hot mix asphalt (HMA). This device is essentially the second generation of the Georgia Loaded Wheel Tester. It measures rutting potential by applying a moving wheel load to the surface of an HMA sample through a pressurized linear hose.
This study was conducted to evaluate the density gradients in samples compacted with methods common to the Asphalt Pavement Analyzer. Both beams compacted with the Asphalt Vibratory Compactor (AVC) and cylinders compacted with the Superpave Gyratory Compactor were included. In order to realistically compare the two modes of compaction, cylindrical specimens compacted with the AVC were also included.
Data accumulated from this study showed that the two compaction methods did produce different density gradients within samples. Vibratory compaction produced a density gradient where the highest density was at the top of the sample and subsequently the density was less toward the bottom of the sample. Gyratory compaction resulted in less density in the top and bottom of samples and more compaction in the middle of the sample.