What are the required dimensions of a metal strike-off plate as per standard C138?

The required dimensions for a metal strike-off plate as specified in standard C138 are indeed rectangular, with a thickness of 1/4 inch and a length/width of 2 inches or greater. This standard provides specific requirements to ensure consistency and accuracy when measuring the volume of concrete samples. The thickness of 1/4 inch is important as it allows for durability and stability while performing the strike-off process, ensuring that the plate does not bend or flex significantly under pressure. Additionally, the minimum dimensions of 2 inches ensure that the plate is large enough to effectively cover the area of the sample while still being manageable for handling.

Understanding these specifications helps ensure that the concrete measurements are precise, which is critical for achieving the desired performance characteristics in concrete applications.