Bulking of Sand:

Bulking of Sand:

The presence of moisture in sand increases the volume of sand. This is due to fact that moisture causes film of water around the sand particles which result in the increase of volume of sand. For a moisture content of 5 to 8 percent, the increase in volume may be about 5 to 8 percent, depending upon the grading of sand. The finer the material, the more will be the increase in volume for a given moisture content. This phenomenon is known as bulking of sand. When moisture content is increased by adding more water, sand particles pack near each other and the amount of

bulking of sand is decreased. Thus the dry sand and the sand completely flooded with water have practically the same volume. For finding the bulking of sand, a test is carried out with following procedure as in the fig

I. A container is taken and it is filled two third with the sample of sand to be tested.

II. The height is measured, say 20cm.

III. Sand is taken out of container

IV. The container is filled with water

V. Sand is then slowly dropped in the container and it is thoroughly stirred by means of a rod.

VI. The height of sand is measured say 16cm, then bulking of sand =

      20 – 16           4

= -------------- = ------ = or 25%

          16              16