Under what circumstances should a CTI request a replacement load?

• A. When the truck arrives late.
• B. When the customer requests it for convenience.
• C. When the batch design has an error but the load meets requirements.
• D. When the load cannot meet required properties after adjustments or safety concerns exist.

Answer: (D)

The key idea is that a replacement load is needed only when the current batch cannot meet the required properties after attempts to fix it, or when there are safety concerns with the load. This means if adjustments (like tweaking mix proportions, temperature control, or workability) bring the load into spec, there’s no replacement. But if those adjustments can’t achieve the required properties or there’s a safety issue that could affect performance or safety on the job, a replacement should be requested to ensure the concrete will perform as specified.

Why the other scenarios don’t fit: arriving late is an operational timing issue, not a quality failure of the concrete, so it doesn’t justify a replacement. A customer requesting a replacement for convenience is not a quality or safety basis for discarding a load. If there’s an error in the batch design but the actual load still meets all requirements, there’s no need to replace—the load is still compliant with the specs.