A new approach to maximising the benefits of current intelligent compaction technology for asphalt materials

This paper investigates the correlations between asphalt density, intelligent compaction measurement values (ICMVs) and asphalt moduli obtained from different laboratory experiments at various temperatures of the asphalt mix AC14 with C320 bitumen. It was found that the influence of the density of asphalt on its modulus is primarily governed by the temperature of the asphalt mix. To examine the influence of asphalt temperature on ICMV-density correlations, a vibrating hammer instrumented with an accelerometer was employed to compact cylindrical asphalt specimens at different temperatures. The correlations between ICMVs and asphalt density at different temperatures showed that ICMVs are insensitive to the change in asphalt density at typical compaction temperatures. A practical method to maximise the benefits of the current intelligent compaction (IC) technology for quality control (QC)/quality assurance (QA) of asphalt pavements is proposed in this study. The proposed approach involves overlaying the ICMV map produced during the pre-mapping of the existing layer and the surface temperature map produced during the final roller pass of the newly-laid asphalt layer compaction to identify the most vulnerable regions for random spot density tests. The effectiveness of this approach was demonstrated for an asphalt overlay testbed compacted using an instrumented vibratory roller.