How is the concrete batch classified if one of the three cylinder compressive strengths falls below 4500 psi?

In concrete quality control, the compressive strength of concrete is a critical parameter for determining its suitability for structural applications. Concrete is typically specified with a target compressive strength, and a common standard is 4500 psi.

When evaluating the strength of concrete samples, the general practice is to consider the results from multiple cylinder tests. If even one of the three cylinders tested produces a compressive strength below the specified limit of 4500 psi, it indicates that the batch does not meet the quality requirements established for the project.

This failure can be indicative of potential issues such as improper mixing, inadequate curing, or poor material quality. In such instances, the entire batch is classified as having non-acceptable compressive strength because the performance of the concrete cannot be assured, which can lead to structural integrity concerns.

Recognizing that structural safety and performance standards are paramount, any sample result that does not meet prescribed specifications leads to the classification of the concrete as non-compliant. Therefore, the correct classification is that the concrete batch is deemed non-acceptable based on the failure of one of the tested cylinders to reach the necessary compressive strength threshold.