Why is it important to dry fine aggregates before gradation testing?

Drying fine aggregates before gradation testing is crucial to eliminate the impact of moisture content on the test results. When aggregates are wet, the moisture can add to their weight, leading to inaccurate measurements of both the mass and the volume of the sample. This can skew the gradation results, which in turn affects mix design calculations and the overall quality of concrete or asphalt mixtures.

Accurate gradation testing is vital for determining if the aggregate meets the specified criteria for size distribution, which impacts the strength and durability of the final product. By drying the aggregates, you ensure that the test solely reflects the physical characteristics of the particles themselves, rather than their moisture-laden weight. This contributes to more reliable data for engineers and contractors in the construction process.