Laboratory tests - Standard test methods

Bulk density

To measure the volume to weight ratio for moist or dry sand, the two methods used are:

Quick Determination Method - Dry Sands

Apparatus

100 ml measuring cylinder, 1 ml graduation accuracy

Balance ± 1g tolerance.

Method

A known weight of dry sand {X) grams is placed into a measuring cylinder. It is gently tilted to one side and then returned to vertical - the reading in ml is then taken from the top of the sand level {Reading A).

The measuring cylinder is then repeatedly tapped on a bench or with a ruler carefully until the sand level is constant; this is then recorded {Reading B).

The results are then expressed in bulk density for the loose and compacted state i.e.

Accurate Determination Method - Moist or Dry Sand

Apparatus

3 litre cylindrical metal container

Metal tamping rod

Large scoop

Balance ± I g tolerance

Method 1 - Uncompacted

Fill the tared three litre container to overflowing with dry sand using the large scoop, by pouring from a height not exceeding 50mm above the container. Strike off the surplus sand with a straight edge across the top of the container and weigh the mass of sand {A)Kg remaining in the container.

Bulk density uncompacted = A / 0.003 = Kg/m³

Method 2 - Compacted

Fill the tared three litre container about one third full with dry sand as described in Method 1. Tap to level the sand surface and then compact by allowing the tamping rod to fall freely from a height of 50 mm above the sand surface, with a sufficient number of drops to cover the whole surface area. Add a similar quantity of sand and repeat the exercise. Finally, fill the container to overflowing and repeat the exercise once more. Strike off the surplus sand with a straight edge across the top of the container and weigh the mass of sand {B)Kg remaining in the container.

Bulk density compacted = B / 0.003 = Kg/m³

The tests may equally be used to determine the bulk densities of moist sand, when it may also be useful to determine and quote the moisture content.

Note:

Standard three litre bulk density measures and tamping rods are readily available from Aggregate test equipment suppliers.

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