How should moisture in aggregates be accounted for when batching?

• A. Ignore moisture because it averages out.
• B. Increase cement content to compensate for moisture.
• C. Adjust batch water and moisture corrections per mix design to maintain target slump and strength.
• D. Use dry aggregates only to prevent moisture effects.

Answer: (C)

Moisture in aggregates changes the actual amount of water in the mix, which directly affects the water-cement ratio, workability, and strength. The right approach is to measure the moisture content of both coarse and fine aggregates and adjust the batch water according to the mix design’s moisture corrections so the target slump and strength are maintained. This means adding or subtracting water based on how much moisture the aggregates are carrying, ensuring the total water matches what the design specifies. Ignoring moisture, bumping up cement to compensate, or using only dry aggregates would introduce variability, waste cement, or ignore field conditions—none of which keep the batch within spec.