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.
- 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
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.
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.
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)