Asphalt Mix Compactors

The Rutgers Asphalt/Pavement Laboratory (RAPL) has four different compactors. Two gyratory compactors that are used for the Superpave design method. The gyratory compactor uses a kneading-type of compaction motion to produce asphalt samples. The molds used compact a sample of 150 mm in diameter and up to 200 mm in height. The ram pressure applied to the sample is 600 kPa, with an angle of gyration of 1.25 degrees. (Figure 10)

RAPL also has a vibratory compactor. The vibratory compactor uses a vibrating plate with a vertical force to compact the asphalt samples. The vibratory compactor can create either round (pill) or brick samples. The vibratory compactor is typically only used when compacting brick samples for testing in the Asphalt Pavement Analyzer (APA). (Figure 11).

The fourth compactor at RAPL is the Marshall compactor. This compactor uses an impact type of compaction method. A blow of 10 lbs at a drop of 18 inches is applied to the asphalt mix. The number of blows depends on the type of asphalt mix to be compacted.

Figure 11 - Vibratory Compactor Used for Compacting Brick Samples