Humboldt H-4340 Sand Equivalent Test Set with Case - Manual (Page 5)

Materials
Stock Solution - The materials listed below will be required:
•
454 g (1 lb) of technical grade anhydrous calcium chloride,
• 2050 g (1640 ml) .of USP Glycerin, and
• 47 g (45 ml), cif formaldehyde (40 volume % solution).
Dissolve the 454 g of Calcium chloride in ½ gal (1.89 litres) of distilled water. Cool and
filter through ready-pleated rapid filtering paper. Add the 2050 g of glycerin and·
the 47 g of formaldehyde to the filtered solutlon, mix well, and dilute to 1 gal.
(3.78 litres)
Working Calcium Chloride Solution - Prepare the working calcium chloride solution by
diluting one measuring tin full of the stock calcium chloride solution to 1 gal. (3.8 litres)
with water. Use distilled or demineralized water for the normal preparation of the working
solution. However, if it is determined that the local tap water is of such purity that it does
not affect the test results, it is permissible to use it, instead of distilled or demineralized
water except in the event of dispute.
NOTE 3: The effect of local tap water on sand equivalent test results may be
determined by comparing the results of three sand equivalent tests using distilled
water with the results of three sand equivalent tests using the local tap water. The six
test specimens required for this comparison shall be prepared from the same sample of
material and oven-dried as prescribed in this method.
Sample Preparation
• Obtain at least 1500 g of material passing the No. 4 (4.75 mm) sieve in the following
manner:
1. Separate the sample on the No. 4 (4.75 mm) sieve by means of a lateral and vertical
motion of the sieve, accompanied by a jarring action so as to keep the sample
moving continuously over the surface of the sieve. Continue the sieving until not
more than 1 weight % of the residue passes the sieve during 1 min. The sieving
operation may be performed either by hand or by a mechanical apparatus. When
thoroughness of mechanical sieving is being determined, test by the hand method
described above using a single layer of material on the sieve.
2. Break down any lumps of material in the coarse fraction to pass the No. 4
(4.7 5 mm) sieve. A mortar and rubber-covered pestle or any other means that will
not cause appreciable degradation of the aggregate may be used.
3. Remove any coatings of fines adhering to the coarse aggregate. These fines may be
removed by surface-drying the coarse aggregate, then rubbing between the hands
over a flat pan.
4. Add the material passing the sieve obtained in 1 and 3 to the separated fine
portion of the sample.
• Prepare test specimens from the material the No. 4 (4.75 mm) sieve portion of the
sample by the procedure described in either 1 or 2 above.