Parameters to Define the Laboratory Compaction Temperature Range of Hot-Mix Asphalt
Rachel De Sombre, David E. Newcomb, Bruce Chadbourn, and Vaughn Voller
Abstract
Proper pavement construction, including asphalt mixture compaction will help ensure good performance
during the life of the road. Knowing the range of temperatures over which the compactive effort of the
asphalt is maximized will help to ensure compliance with compaction specifications. The objective of this
program was to define the asphalt mixture temperature range in which the desired density can be achieved.
In this study, a gyratory compactor was used to compact samples at different temperatures. Density data
were recorded at several points during compaction. The density data, the change in height of the sample
during compaction, the size of the sample, and the pressure used to compact the sample were used to
calculate the total work done during compaction. By plotting the shear stress and power used during
compaction against the number of gyrations for each temperature, the compactability of the mixtures was
evaluated. By testing samples at several temperatures it was possible to determine a desirable range of
compaction temperature for a given mixture.
It is especially useful to know this range of temperature for compaction during late season paving when
air temperature and weather conditions are typically unfavorable for paving. The interval of time where the
most efficient compaction can occur is drastically shortened, making it necessary to know the minimum
temperature for effective compaction.