Why is it necessary to seal cement and fly ash samples properly?

Sealing cement and fly ash samples properly is crucial primarily because it helps prevent contamination and moisture from affecting the sample. When samples are exposed to the environment, they can absorb moisture, which can alter their properties and ultimately impact the results of testing. For instance, excessive moisture can lead to premature hydration of the cement or changes in the physical characteristics of the fly ash, potentially skewing test results and leading to incorrect conclusions about their performance or compliance with project specifications.

Additionally, contamination from dust, other materials, or environmental pollutants can introduce foreign substances into the sample, affecting its composition and the reliability of testing outcomes. Proper sealing ensures that the integrity of the sample is maintained from the point of collection through storage and transportation to the testing laboratory. These factors emphasize the importance of sealing samples correctly to uphold the quality and reliability of materials used in construction.