What might result if an overly coarse soil is used in the sand cone method?

Using overly coarse soil in the sand cone method can lead to inaccurate density measurements. This is primarily because the sand used to fill the hole created during the test may not adequately fill the voids of the coarse soil due to its larger particle sizes. When sand particles do not properly settle into the spaces between larger soil particles, it results in a measurement that does not accurately reflect the true volume of the coarse soil. Consequently, when calculations are made to determine the density, the results will be skewed.

In contrast, if the soil were suitable in grain size, the sand would fill in the gaps more effectively, allowing for a reliable calculation of density. Therefore, the integrity of the measurement is compromised when incompatible soil textures are involved, emphasizing the importance of selecting an appropriate soil type for accurate testing results.