Sand Filling Cylinder

Site bulk density test method—measured by sand filling method

Bulk density of fine-grained and medium-grained soils or density of medium- and coarse-grained soils

2. Scope of application:

This test method is suitable for measuring the bulk density of sandy soil, sandy soil and mixed sand and gravel, cement stabilized soil, affordable stabilized soil, etc. on the construction site. The maximum particle size of the above aggregates shall not exceed 25 mm. The measured bulk density does not exceed 150 mm.

Equipment ：

1. The sand filling cylinder is made of iron plate and steel pipe (plastic), with an inner diameter of Φ100 mm and a total height of 360 mm. Millimeter round hole, standard filling Φ100mm, height 150mm.

2.The inner diameter is Φ150mm, the total height is 360mm, the cylinder depth is 270mm (volume is about 4771cm3), there is a Φ15mm round hole in the center of the bottom of the cylinder, the calibration irrigation is Φ150mm, and the height is 150mm.

3.The inner diameter is Φ200mm, the total height is 360mm, the cylinder depth is 270mm (volume is about 8482cm3), there is a Φ20mm round hole in the center of the bottom of the cylinder, the calibration irrigation is Φ200mm, and the height is 150mm.

Calibration of the instrument：

The steps to determine the sand weight in the lower cone of the sand filling cylinder are as follows：

1. Fill the sand storage cylinder with sand, the height of the sand in the cylinder and the distance from the bottom of the cylinder is more than 15 mm, and the weight of the sand in the cylinder should be accurate to 1g (m1). This weight should be maintained for each calibration and subsequent tests.
2. Turn on the switch, let the sand flow, and make the volume of the outflow sand and the weight of the sand in the test hole dug at the construction site to be accurate to 1g (m3). When the sand is no longer flowing, turn off the switch and carefully remove the sand filling cylinder.

3. Collect and weigh the sand left on the glass plate to the nearest 1 g. This sand is the sand that fills the lower cone of the sand filling cylinder.
4. Repeat the above measurement at least three times and finally take the average value, accurate to 1g (m2)
5. Determine the unit specific gravity rg (/cm3) of the sand. The steps are as follows:

• Determine the volume V (cm3) of the calibration irrigation with water.

（2）Load the sand with a weight of m1 into the sand tank, put the sand tank on the standard tank, turn on the switch, and let the sand flow out (do not touch the sand tank during the whole quicksand process to weigh the remaining sand in the tank, Accurate to 1g.

Repeat the above measurement at least three times and finally take the average value, accurate to 1g

Calculate the weight m2 of sand required for calibration irrigation by the following formula

m₂—m₁—m₂—m₃

m1—the weight g of the sand in the cylinder before filling the sand into the calibration filling

m2—the average weight g in the lower cone of the sand filling cylinder

m3—the weight g of the remaining sand in the cylinder after filling the sand into the standard filling

Calculate the specific gravity of sand using the following formular2（g/cm3）

R2 =m2/V in the formula V — Calibrated irrigation volume (CM3)

Calculate the wet capacity of the soil at the test site and stabilized soil using the following formularw（g/cm3）

rW=mW X r2mb

In the formula, mW—the bulk density g of all the soil taken out from the test hole

mb—the weight of the sand required to fill the test hole, g, r3—the specific gravity of the sand in g/cm2

Calculate the dry capacity of soil or stabilized soil using the following formulard（/cm2）

rd=rW（1+W%）

In the formula, w is the moisture content of soil or stabilized soil. In the field of cement stabilized soil or lime stabilized soil, or use the following formula to calculate its dry capacityrd（g/cm3）

rd=md X r/md

In the formula, md—thousand capacity (g) of the stabilized soil taken out from the formula