What is the typical time limit for operating a mechanical shaker during aggregate testing?

The typical time limit for operating a mechanical shaker during aggregate testing is generally set between 7 to 10 minutes. This duration is established to ensure that the aggregates are adequately separated and classified without risking over-saturation or damage to the samples.

In this time frame, the mechanical shaker operates at a consistent vibration intensity, allowing for thorough stratification of the materials based on size. If the shaking period is too short, it may not be sufficient to achieve consistent results, whereas if it’s too long, it might cause excessive mixing or degradation of the material being tested. This balance is crucial in achieving reliable aggregate testing results, which are vital for quality control in construction projects.

The other options suggest either shorter or longer durations which may not align with established testing protocols, potentially impacting the accuracy and reliability of the results.