Visualization and quantification of lab vibratory compacting process for aggregate base materials using accelerometer

Although being widely used as the quality control for field compaction, neither the standard nor modified Proctor tests match the compaction effort of existing field compaction machineries commonly used today. More importantly, these methods are incapable of identifying the compactability of soil materials other than maximum dry density and optimum moisture content. With the widespread application of intelligent compaction (IC), there is a need to develop a new laboratory compaction method for soil and aggregate materials in which a detailed compaction process could be visualized or quantified. In this study, a lab scale vibratory compactor, asphalt vibratory compactor (AVC), was adopted to compact an aggregate base material with a mounted accelerometer. Based on dry density-moisture content curves, the AVC compaction was more effective in compacting cohesionless soils than the standard Proctor test, and there existed an optimum AVC parameter setting to acquire the highest dry density of aggregates as well as more stable frequency spectrums. In addition, by using the discrete-time Fourier transform the lab compaction process could be visualized through the frequency-domain spectrums. Two IC parameters, Compaction Meter Value (CMV) and the Compaction Control Values (CCV), were calculated for specimens at different water content. The CCV value had a more stable pattern and two distinct compaction stages could be identified for the lab compaction, which could be used to construct the lab compaction curve. Based on the lab compaction curves, AVC has the potential to identify the moisture content and compactability of soil materials and to guide the field compaction.