What pressure should be maintained for the gyratory compaction according to standards?

The appropriate pressure for gyratory compaction, according to industry standards, is 600 +/- 18 kPa. This specific pressure is established to ensure that the density of the asphalt mixture being compacted closely simulates the density achieved in the field. Maintaining this pressure range allows for consistent results during testing, which is critical for the evaluation of the mixture's performance characteristics, including stability and durability.

Higher or lower pressures could lead to inadequate compaction, either resulting in a mixture that is not representative of actual field conditions or potentially damaging the asphalt structure during testing. The standardization of this pressure helps to maintain uniformity across different tests and laboratories, ensuring that results can be reliably compared and used for quality control in asphalt production and placement.