Evaluation of Optimal Compaction Frequencies for Granular Materials

Road material compaction is achieved through the application of various types of rollers to the pavement layer. The use of vibration compaction is quite prevalent, where the vibration frequency and amplitude can be optimized to obtain optimum density for the material that is being compacted. In this paper the vibrations measured in the field during vibratory compaction of pavement layers consisting of different materials are compared to the results of vibration table compaction in the laboratory at a range of frequencies to determine the effect of frequency on the optimum densities for the different materials, and the relationship between the applied roller frequencies and the densities achieved. The frequencies inside the material and on the roller drum are monitored and compared with the frequencies applied in the laboratory on the vibration table, and the resultant densities achieved or three different base layer materials. The data indicate the importance of selecting appropriate frequencies for different types of road building material to enable optimal compaction.