Which aspect of the paving operation is most impacted by ambient temperature?

The aspect of the paving operation that is most impacted by ambient temperature is asphalt viscosity. Viscosity refers to the thickness and flow characteristics of the asphalt binder, which dramatically changes with temperature fluctuations. When the ambient temperature is high, the viscosity of asphalt decreases, allowing it to flow more easily and become less resistant to deformation. This facilitates the proper mixing and placement of the asphalt during the paving process.

Conversely, when temperatures drop, the viscosity increases, which means the asphalt becomes thicker and less workable. This can lead to difficulties in achieving proper compaction and a well-formed mat. Paving operations must carefully consider asphalt viscosity, as it influences not only the workability of the mix but also the final performance characteristics of the pavement.

While mix design, paver speed, and rolling patterns have their own relationships with temperature, they are not as directly affected by ambient temperature as asphalt viscosity is. High temperatures may alter how a mix is designed or affect rolling efficiency, but it is the viscosity that fundamentally determines how the asphalt behaves in response to temperature changes during paving operations.