InstroTek
28
Procedure:
1.
Set CoreLok to Program #2 using the up and down arrows on the front panel.
2.
Inspect an appropriate size bag for holes or stress point. Do not use the bag
if it is damaged.
3.
Obtain an empty bag weight, record in Column A of the Porosity Data
Collection Sheet
(pg. 29).
4.
Weigh a compacted and dry asphalt specimen.
5.
Record the dry sample weight in Column B.
6.
Seal the sample inside the bag using the procedures outlined on page 16.
7.
Submerge the sealed sample and wait until the scale stabilizes.
8.
Record the weight in Column C.
9.
While the sample is still submerged under water, cut the bag open with
scissors.
10.
Allow water to enter the bag.
11.
Leave the sample under water for at least 4 minutes. Make sure the bag is
not floating out of the water and it is not touching the sides or the bottom of
the tank.
12.
Record the weight in Column D.
Calculations:
The calculations can be performed by using the Porosity program in the
provided GravitySuite
software. Just input the weights in the columns provided
and the program will automatically calculate % Porosity. Also, if you input the
maximum specific gravity (Gmm) in the program, % Air Voids is calculated for
comparison purposes.
Alternatively, you can use the standard equations given in ASTM D6752 to
calculate the bulk sealed density of the sample,
1,
and ASTM D6857 to
calculate the apparent (or maximum) density,
2,
of the compacted sample.
Use the equation given above to calculate %Porosity.
