Thickness measurements are only valid on specimens cored in the field; Marshall or SUPERPAVE specimens have an alternate method for measurements.

• A. True
• B. False
• C. They have an alternate method for measurements
• D. They require no measurement

Answer: (B)

Thickness is a dimension used in volumetric calculations and must be known for any asphalt specimen, not just field cores. In the field, thickness is measured directly on cores because surface irregularities can affect readings, so multiple measurements are averaged. In the lab, Marshall or SUPERPAVE specimens are made in fixed-dimension molds, so their thickness is controlled by the mold and compaction; if needed, you can verify it by measuring the finished specimen height or by using the mold’s known height as the standard. Because there is a valid method to determine thickness for lab specimens as well, thickness measurements are not restricted to field cores.