Florida DOT Concrete Batchman/Operator Practice Exam

What corrections must be applied when weighing aggregates?

1. Weather corrections

2. Surface moisture corrections

3. Environmental corrections

4. Density corrections

The correct answer is: Surface moisture corrections

When weighing aggregates, surface moisture corrections are necessary to ensure accurate measurements of the materials used in concrete production. Aggregates can retain moisture on their surface, which can lead to an incorrect weight measurement if not accounted for. When aggregates are weighed directly, the moisture present can add weight that is not part of the dry aggregate mass needed for the concrete mix design. As a result, the amount of cement and water added might be skewed, potentially affecting the strength and durability of the final concrete product. Applying surface moisture corrections allows for the precise quantification of the aggregate needed, ensuring that the specified mix design is accurately followed. This correction helps to maintain consistency in concrete performance and quality by compensating for any additional weight from moisture that could otherwise distort the ratio of materials used in the mix. Other corrections, while important in specific contexts, do not directly address the immediate need for adjusting the weight of aggregates during batching when surface moisture is present.