Florida DOT Concrete Batchman/Operator Practice Exam

To what accuracy should the scales for weighing cement, pozzolan, slag, and aggregates at the plant be maintained?

1. 1.0% of the maximum load normally handled

2. 0.5% of the maximum load normally handled

3. 0.1% of the maximum load normally handled

4. 5.0% of the maximum load normally handled

The correct answer is: 0.5% of the maximum load normally handled

The scales used for weighing materials like cement, pozzolan, slag, and aggregates need to be maintained at a high level of accuracy to ensure that concrete is produced with the correct proportions. This is crucial because even small variations in the quantities of these materials can significantly affect the strength, durability, and overall quality of the concrete. Maintaining the scales to an accuracy of 0.5% of the maximum load normally handled strikes a balance between precision and practicality. This level of accuracy allows for sufficient control in the batching process, ensuring the desired mix proportions are achieved consistently. Concrete mix design specifications often emphasize the importance of accurate measurements for all components since discrepancies can lead to performance issues in the finished product. The higher accuracy options, such as 0.1% of the maximum load normally handled, while ideal for highly specialized applications, may not be necessary and could be impractical for typical batch operations. On the other hand, lower accuracy levels, like 1.0% or 5.0%, could lead to significant variations that might compromise the quality and structural integrity of the concrete. Therefore, the selected accuracy of 0.5% is the standard for ensuring reliable and consistent concrete production.