When sampling from a paving mixer, how many different portions of the pile should be obtained to create a composite sample?

To create a composite sample from a paving mixer, obtaining two different portions of the pile is generally considered the minimum standard. This approach helps ensure that the sample taken is representative of the entire batch, thereby enhancing the reliability and accuracy of the test results.

Collecting just one portion would not adequately represent the variability that can exist within the pile, as a single sample may be influenced by localized differences in the material. Two portions allow for some basic averaging of different areas within the pile, thus providing a more holistic view of the material characteristics. This method also helps mitigate the impact of any anomalies that might exist in a singular sample, making it a standard practice in materials sampling for quality testing.

More portions can certainly be gathered for increased accuracy, but with two portions, a sufficient foundation for a composite sample is established, balancing practicality and representativeness effectively.