 
This video demonstrates
the Sand Equivalent Test.
Conducting this test
provides a measure
of how much clay is contained
in an aggregate sample.
The test is completed
on aggregates
used for asphalt paving
mixtures and also for aggregates
used for microsurfacing
projects.
The Sand Equivalent
Test is important
because aggregates that contain
a large amount of fine dust
or clay can have an adverse
effect on the performance
of an aggregate and asphalt mix.
The extra dust or clay
prevents the asphalt
from properly binding
to the aggregate
and that may cause the road
to break down much faster.
North Dakota uses
alternate method two
and performs two
trials of the test,
and then averages the
results of the two tests.
The Sand Equivalent
Test is the only test
that requires you
to always round up
the results to the
next higher number.
First, collect the equipment
to conduct the test.
You need a pan, trowel
or spatula, water bottle,
damp cloth, and plastic
splitting cloth.
You also need two three-ounce
sample tins with covers.
You need a funnel,
graduated plastic cylinder,
weighted foot assembly,
timer, and a rubber stopper.
In addition, you need some
calcium chloride solution
and irrigation tube and a
mechanical sand equivalent
shaker.
Next, obtain an aggregate
sample and then reduce it
to testing size.
The sample should be
approximately 1,000 to 1,500
grams of unwashed minus
number four material.
Place the sample in a pan.
If the sample is
dry, you will need
to add water and thoroughly
mix until it is damp enough
to hold a cast.
If the sample is already damp,
you may not need to add water.
 
In either case, the sample
must be moist enough
to hold a light cast when
squeezed in your hand.
 
It is important to
thoroughly mix the sample
so the moisture
content is uniform.
 
After you have determined the
sample is at the right moisture
content, cover with
the damp cloth.
Make sure the
cloth does not come
into contact with the sample.
Let the sample sit for
a minimum of 15 minutes.
This allows the aggregate
to absorb the moisture.
 
Next, pour the sample onto
a non-absorbent splitting
cloth and mix.
Mix the sample by pulling
from corner to corner.
Mixing the material this way
is similar to the test method
for reducing an aggregate
sample on a quartering cloth.
After thoroughly
mixing the material,
the sample should be in
the center of the cloth.
Take the three-ounce
sample container
and place a hand on
one side of the pile
and the sampling container on
the other side of the pile.
Push the can through
the sample to your hand
on the opposite
side, then firmly
push the sample into
the can with your hand
to cause it to overfill.
Strike off the material above
the top of the can and cover.
 
Next, remix the sample,
pulling the cloth from corner
to corner, bringing the
sample over the top of itself.
 
Take the second tin and
repeat the procedure, bringing
the sample container
in your hand
together, pushing the
material into the sample can.
Strike off the top of the can.
 
After preparing the sample,
pour four, plus or minus a tenth
of an inch, of calcium chloride
solution into a cylinder.
 
Add the material from one of
the tins into the cylinder.
Take care not to
lose any material.
 
Sharply strike the
bottom of the cylinder
with the palm of your hand to
remove any air bubbles that
may be trapped in the
bottom of the cylinder.
Now, let the sample
stand undisturbed for 10,
plus or minus one, minute.
 
Securely place the
stopper on the cylinder
and shake loose the
material from the bottom.
 
Place the cylinder into the
mechanical shaker for 45,
plus or minus one, second.
 
After the 45 second
shake period,
remove the cylinder
from the shaker
and then remove
the stopper, being
careful not to
lose any material.
 
Then, add calcium
chloride solution
up to the 15 inch line.
When doing this,
wash any material
that may be sticking to the
sides of the cylinder walls.
When flushing the sample,
push the irrigation tube
down to the bottom of
the sample in a twisting,
turning motion while filling.
This flushing and twisting
will wash the fines
from the bottom of the sample
and bring them into suspension.
Continue this
procedure until you
are close to the 15 inch mark.
 
When nearing the 15
inch mark, be prepared
to pull out the irrigation
tube at the same time
the cylinder fills
to the 15 inch mark.
Let the sample sit undisturbed
for 20 minutes, plus or minus
15 seconds, to allow
sedimentation to occur.
At the end of the 20
minutes sitting period,
check the sample and
determine the clay reading.
If the reading is in
between two marks,
record to the next
higher number.
 
Next, take the
weighted foot assembly
and carefully lower
it into the cylinder.
 
Take the sand reading.
Again, if the reading
is in between two marks,
round up to the next higher
number and then subtract 10.
10 is the distance
between the bottom
of the weighted foot and
the reading indicator.
Repeat the process
on the second sample.
When completing the Sand
Equivalent Test calculations,
round the results of each
test to the next higher whole
number.
Then, average the two
numbers, and again,
around the average up to the
next higher whole number.
 
