Pavement

A pilot study examined the feasibility of using laboratory produced mix compaction curves to indicate the relative workability (ease of compaction) of asphalt mixes in the field. Five mixes of different expected workabilities were used. A roller segment slab compactor was used as a surrogate for roller compaction in the field. This compactor was modified to record air void content each compaction cycle. The compaction curves produced were compared to those from Gyropac and Servopac gyratory compactors for the same mixes. For four of the five mixes a single equation related Gyropac cycles to produce particular air void contents to slab compactor cycles to produce the same air void contents. This suggests that a gyratory compaction curve can be used to indicate the relative compactive effort needed in the field to achieve a target voids content. There were differences between Servopac and Gyropac results and, once the reason for this anomalous behaviour is determined, further work will be undertaken to verify the provisional findings.