Sand Cone Test (ASTM D1556)
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Sand Cone Test (ASTM D1556)

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     Sand Cone Test- ASTM D1556     


 

 The sand cone test has been widely used for many years to determine in-place field density     for more cohesive soil.

- Apparatus.

Sand cone: Aluminum funnel and glass or plastic jar (with plastic being preferred).


Aluminum base plate

Bucket or container to hold the soil removed from the hole.

Scale: 1 kg scale accurate to 0.1 g and 20 kg scale accurate to approximately 1 g.

Camp stove or oven: for moisture burn-out.

Pan or container: for moisture sample.

Digging tool: Scoop or large spoon, screwdriver or chisel and paint brush.

# 20 or # 30 silica sand.


- Preparation

- Test preparation at laboratory.

Before beginning the actual sand cone test the cone and plate must be calibrated to indicate the average weight of the sand it takes to fill their volume. To do this, put amount of sand inside the sand cone jar and then weight it (W1).

Put sand cone on the horizontal surface with the aluminum base plate then turn on the valve to allowing the sand to flow and fill the bottom cone.

Close the valve and weight the sand cone jar with the sand remaining in it (W3).

The weight of the sand filling the cone is calculated as following:

WC = W1 – W2

Fill sand cone jar again with sand and weight it (W3).

The cone jar nozzle is placed on the opening of a standard container of a know size whose dimensions are regular so that the volume of the container can be estimated (Vn). It should be the diameter of the cone nozzle.

Open the valve to allowing sand flow from sand cone to fill the standard container and of course the cone part.

Close the valve and weight sand cone jar with sand remaining on it (W4).

From W4 and W3 we can calculate the weight of sand which fill a standard container (Wn) by knowing the weight of the sand that fills the cone (Wc) as follow:

Wn = W3-W4-Wc

The density of the standard sand is calculate when it is poured from the jar and passes from the valve opening to the standard cone by dividing the weight of the sand filling the container (Wn) by the volume of container (Vn) as follow

γs = Wn/ Vn gr/cm3


 - Test procedure at site.

Carry the sand cone, base plate, bucket and digging tools to the area to be tested.
Drill the soil from a circular hole in the base plate by a coop, spoon, or other suitable digging tool. The drilling continue until reaching a cylindrical hole approximately equal in depth to the laboratory standard container and the drilling product is placed in a plastic bag and sealed.





Be sure that all the material removed from the hole is placed into a plastic bag. Any soil that has fallen into the base plate during the digging process and cannot easily be put into the plastic bag should be swept back into the test hole with a brush and then patted into place with your hand.

Weight the plastic bag with the soil to know the wight of the soil extracted from the hole in its natural state (W)

The sand jar with a cone is weighted (W5) then place the sand cone on to the base plate over the hole. Be sure the funnel is properly seated into the groove of the base plate.



Then open the valve to pour sand from the jar to filling the hole plus of course the cone.

Do not tap the cone or funnel during the test. Also be sure that there is no vibratory equipment working close to vibrate the sand, which could lower the test result because more sand would vibrate into the hole than would normally take place from gravity flow only.

Close the valve and take the sand cone jar and weight it (W6)

Calculation the weight of the sand that fills the hole (Wh) as following:

Wh = W5 – W6- Wc  (gr)

With the sand density measured before at laboratory (γs), the volume of sand that filled the hole (V), which meaning that size of the hole, is calculate as following:

V = Wh / γs   gr/cm3


The field soil density at site is calculate as following:

γb = Wh/ γs


the moisture content of the soil extracted from the hole W% is determined as per proctor test which explained in previous article (Modified Proctor Test )

calculation the soil dry density (γd ) as following:


 γd = γb / 1+ W%  (gr/cm3)










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