How does ambient temperature affect delivered HMA mixture?

Ambient temperature plays a significant role in the performance and characteristics of the delivered Hot Mix Asphalt (HMA) mixture. When the ambient temperature is lower, the delivered HMA will cool at a faster rate. This cooling rate can impact the workability of the mixture, as well as the time available for compaction. If the mixture cools too quickly, it may become too stiff to compact properly, which can lead to a less durable pavement surface.

Understanding this effect is crucial for HMA inspectors, as they must monitor temperatures during the paving process to ensure that the mixture retains its workability for an optimal amount of time. By doing so, they can help in achieving proper density and compaction, which are essential for the longevity of the asphalt pavement.