Abstract
<jats:p>Cold-weather asphalt paving is commonly restricted because rapid mixture cooling reduces workability and shortens the compaction window. This study evaluated whether warm-mix asphalt (WMA) combined with heated-drum roller compaction could preserve a usable compaction window and achieve a specification-relevant density at ambient and base temperatures as low as 20°F, which is 25°F below the 45°F Unified Facilities Guide Specifications (UFGS) underlying-surface temperature limit for lifts less than 3 in. Three plant-produced WMA mixtures were compacted as 2 in. slabs using a heated-drum hydraulic roller under controlled ambient and base temperatures from 20°F–85°F and roller delays of 0–20 min after placement. Embedded thermocouples measured precompaction cooling and thermal response during rolling. Density was evaluated using cores extracted from each compacted slab. After quality-control screening, approximately 97% of specimens achieved the 6.0%–8.0% air voids target across all conditions, including at 20°F. Statistical analysis showed that mix, temperature, and delay significantly affected density; the mix-by-temperature interaction was also significant, whereas the temperature-by-delay interaction was not, indicating progressive rather than threshold-based behavior. The heated drum provided localized thermal input at the roller–mat interface despite continued bulk cooling. Results support managing cold-weather paving through compaction-window preservation, mixture-specific evaluation, and outcome-based density verification.</jats:p>