When using rapid dry methods for aggregate, be sure to stir the sample frequently to prevent localized overheating and aggregate fracturing.

When using rapid dry methods for aggregate, be sure to stir the sample frequently to prevent localized overheating and aggregate fracturing.

• A. Do not stir the sample during drying.
• B. Stir the sample only after drying is complete.
• C. Stir the sample frequently to prevent localized overheating and aggregate fracturing.
• D. Increase the oven temperature to speed up drying.

Answer: (C)

Stirring during rapid drying ensures even heat distribution and prevents localized overheating that can cause aggregate fracturing. When heat is applied quickly, outer surfaces can heat up much faster than the inner particles, creating thermal gradients that crack or break the sample. Frequent stirring exposes all particles to heat more uniformly, helps moisture escape evenly, and avoids crusts or hotspots that lead to fracturing, so the moisture reading remains representative. If you don’t stir, hotspots form and the sample can crack, skewing results. Stirring only after drying defeats the purpose during the heating step, and increasing the oven temperature speeds drying but raises the risk of damage and inaccurate readings.

Stirring during rapid drying ensures even heat distribution and prevents localized overheating that can cause aggregate fracturing. When heat is applied quickly, outer surfaces can heat up much faster than the inner particles, creating thermal gradients that crack or break the sample. Frequent stirring exposes all particles to heat more uniformly, helps moisture escape evenly, and avoids crusts or hotspots that lead to fracturing, so the moisture reading remains representative. If you don’t stir, hotspots form and the sample can crack, skewing results. Stirring only after drying defeats the purpose during the heating step, and increasing the oven temperature speeds drying but raises the risk of damage and inaccurate readings.