Determining the Maximum Density of Sands by Pluviation

Experiments have been carried out to find the maximum dry density taken up by sands during pluviation. These experiments were facilitated by use of a flow divider that permitted very low depositional intensities. It was found that the maximum dry density occurred at an optimum pluviation time. Careful observation of the pluviating sand reveals that compaction takes place within an “energetic layer” of 3 to 4 grains in thickness and that maximum dry density requires the full and continuous development of this layer. Further experiments were conducted to compare simple pouring without diffuser meshes with pluviation: it is shown that at very slow rates of pour, pouring gives the same density as pluviation.