How frequently should field samples be taken for quality control on a typical CTI assignment?

• A. For each load or as specified by project requirements; document sampling frequency.
• B. Only once per week.
• C. Never take field samples.
• D. Only for the first load of the day.

Answer: (A)

Field quality control sampling should be done for each load or as the project requirements specify, and the sampling frequency must be documented. This approach captures the variability between loads and provides a timely, verifiable record of concrete properties as deliveries occur. Each load can differ in materials, batching, transit time, and environmental conditions, so checking every load helps detect issues early and supports proper acceptance decisions. Sampling only once per week could miss problems that appear in other loads, while sampling only the first load or never sampling altogether fails to provide reliable QC data. Documenting how often you sample ensures traceability and compliance with project specs.