Under what condition should the pavement temperature be when performing the final straightedge?

The final straightedge check is a critical step in ensuring the quality of the asphalt pavement. Conducting this assessment at ambient temperature is essential because it allows for a more accurate evaluation of the pavement's surface texture and smoothness. Ambient temperature refers to the air temperature surrounding the pavement during the day, which is crucial for determining the asphalt's consistency and performance characteristics.

When the pavement is at or near ambient temperature, the material has had sufficient time to cool and stabilize, thus providing consistent results when measuring for any irregularities. This helps ensure that any necessary adjustments can be made to the pavement before it is subjected to traffic.

Performing the straightedge check at night or while it is raining could lead to misleading results, as cooler nighttime temperatures may affect the pavement's rigidity differently than during the day, and rain can interfere with both the surface quality and the accuracy of the straightedge measurements. Similarly, checking while the sun is shining can result in heat-induced variations, affecting the viscosity and handling of the asphalt, which would not represent the pavement’s performance during typical usage conditions. Conducting the final straightedge test at ambient temperature is key to achieving a reliable assessment of the pavement's surface.