When should the flasks for GMM be filled with water?

Filling flasks for the GMM (Genuine Maximum Density) test with water is a crucial step that helps in achieving the correct water-aggregate contact time necessary for accurate density measurements. Filling the flasks before 9 minutes aligns with the testing protocols, ensuring that the materials have had sufficient time to settle while maintaining accurate timing, which is essential for consistency and reliability in the results.

Completing the filling of the flasks at this stage helps to minimize any discrepancies that could arise from extended waiting periods, which may alter the material's state or characteristics due to hydration or other factors. Time management in laboratory processes is vital for ensuring that the asphalt mixture retains its intended properties during testing. Therefore, adhering to this specific timing maximizes the effectiveness of the test and guarantees that measurements reflect the genuine properties of the asphalt mix.

Following other timing options would either cause delays or could lead to potential inaccuracies in the results, impacting the overall reliability of the GMM determination.