Performance tests require the specimens to be fabricated to a specific height and/or void volume.

• A. Not specified
• B. Unknown
• C. True
• D. False

Answer: (C)

In performance testing, controlling how a specimen is made is essential because the material’s performance hinges on how much air void space it contains. The height (together with the diameter) fixes the specimen’s volume, and when you compact it to a target density, you establish a specific void content. That void content strongly influences how the mix behaves under load—stiffness, rutting resistance, moisture susceptibility, and other properties can change if the voids are more or less than intended. If the height or void volume isn’t controlled, results can vary from one specimen to another due to differences in density rather than real material performance, making comparisons unreliable. Therefore, specimens are fabricated to a precise height and/or a specified void volume to ensure repeatable, comparable test results.