ABSTRACT
ABSTRACT: The terms workability and compactability have been applied to asphalt mixtures to describe the relative ease with which material can be placed, hand worked, or compacted. A number of methods described in literature have been investigated to quantify this parameter, including devices that measure the torque required to rotate a mixing paddle through a sample of asphalt mixture. An improved workability measurement device based on that concept is described in this paper. Data collected with this device for seventeen mixtures are presented. The mixtures included both Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA). WMA was produced with Sasobit® additive, EvothermTM 3G additive, and by asphalt binder foaming. Reclaimed Asphalt Pavement (RAP) contents of 25 and 50% were also investigated for HMA and WMA. Four of the mixtures without RAP, including HMA and one of each WMA, were produced at an asphalt plant and placed into test strips with full scale construction equipment. Compaction of the pavement mat was monitored by embedded thermocouples, and nuclear density gauge measurements were taken between successive roller compactor passes. The relationship between laboratory measurement of workability and the relative ease of field compaction is investigated.
