Florida DOT Concrete Batchman/Operator Practice Exam

What is the minimum normal sampling frequency for the chloride content of structural concrete?

1. 1 per design mix from the first day of production and every 30 days or less thereafter

2. 1 per batch during the first week of production

3. 1 per design mix in the first month of production

4. Every 15 calendar days

The correct answer is: 1 per design mix from the first day of production and every 30 days or less thereafter

The minimum normal sampling frequency for the chloride content of structural concrete is determined to ensure the long-term durability and integrity of the concrete structure. Sampling the chloride content at the specified frequency allows for consistent monitoring of the materials being used, which is critical since excessive chloride levels can lead to corrosion of reinforcing steel within the concrete. The correct choice indicates that sampling should occur once per design mix from the first day of production and at least every 30 days thereafter. This approach allows for initial oversight when a new concrete mix design is introduced, capturing any potential issues early on. Follow-up sampling every 30 days helps to verify that the composition remains consistent and within acceptable limits for chloride content over time. This frequency is crucial in maintaining quality control in concrete production, ensuring that the materials consistently meet the specifications laid out for structural safety and performance. Other options may not provide the same level of ongoing assurance regarding chloride content, which is vital for the longevity of the concrete structures being produced.