METHODS OF SAMPLING AND TESTING HIGHWAY MATERIALS 91 
struction (serial designation D 63-23 T) of the American Society for Testing 
Materials (-5), of either trap or hard limestone shall be placed in a No. 10 sieve, 
drenched and washed with distilled water, allowed to drain for three minutes, 
and transferred to a suitable pan in which the mixture is to be made. (A 6-inch 
hemispherical iron dish has been found suitable and satisfactory for this 
purpose.) Thirty-five grams of the emulsion shall then be added to and mixed 
vigorously with rbe stone for three minutes. (A steel spatula is satisfactory 
for mixing.) There shall be no signs of appreciable separation of the asphalt 
contained in the emulsion during the three-minute mixing period. 
METHOD FOR DETERMINATION OF WATER, OIL DISTILLED WITH 
WATER, AND PREPARATION OF ASPHALTIC BASE FOR FURTHER 
TESTS 
(A) METHOD APPLICABLE TO EMULSIONS OF CLASS II (o) ONLY « 
4. The apparatus shall consist of a copper still 6 inches by 3^ inches in 
inside diameter with an air-adjustable ring burner to fit the still. The still 
shall be provided with a connecting tube of approximately 12-millimeter 
diameter glass tubing, a tin shield, a condenser trough, a condenser tube, and a 
suitable graduated cylinder. A thermometer 0° to 400° C. shall be provided 
conforming to the requirements for the thermometer specified in section 6 of 
the tentative method of test for distillation of creosote oil (serial designation 
D 246-27 T) of the American Society for Testing Materials (5). The appa- 
ratus shall be set up as shown in Figure 36. The still shall be charged with 
200 grams of the well-mixed sample. An oiled-paper gasket shall be applied 
to the flange at the top of the still and the cover clamped on securely. The 
thermometer shall be placed in position so that the tip of the bulb is one-half 
inch from the inside bottom of the still. A gentle heat shall be applied to the 
top of the still by the ring burner. Just sufficient heat shall be applied to the 
connecting tube to prevent condensation of water therein. 
The heat shall be applied to the extreme upper part of the still until 
practically all of the water has distilled over, or until a temperature of 121° C. 
(250° F.) has been reached. The ring burner shall then be lowered very 
gradually to a position midway between the top and bottom of the still and 
held there until the temperature is about 176° C. (349° F.). The ring burner 
shall then be lowered more rapidly to within one-fourth inch of the bottom of 
the still and the temperature then raised to 260° C. (500° F.) and maintained 
for 15 minutes. This period of heating is important to insure a smooth 
homogeneous residue in the still. 
The cover shall then be removed from the still and the hot residue poured 
into a ductility mold and into a standard 3-ounce tin box for the penetration 
tesr. the receptacles being left uncovered. While cooling any excess shall be 
poured into suitable containers for any additional tests desired. 
Any water or oil remaining in the condenser tube shall be forced out care- 
fully into the graduated cylinder by means of a rubber stopper fixed on the 
end of a long rod. 
The distillation should be completed in not less than one hour and in not 
more than one and one-fourth hours. 
If the residue is not homogeneous and appears granular, it shall be rejected 
and the distillation repeated upon a fresh sample, maintaining the temperature 
at 260° C. (500° F.) for slightly more than 15 minutes. 
The number of cubic centimeters of water divided by 2 is the percentage of 
weight of water. 
The weight of residue remaining in the still divided by 2 is the percentage 
of nonvolatile matter under the conditions of this test. m 
The sum of the percentage of water and nonvolatile matter deducted from 
100 represents distilled oils. 
f§) METHOD APPLICABLE TO EMULSIONS OF CLASS II (b) 
Water. — The water shall be determined by the distillation method above 
described. 
13 Method Xo. 51 [page 88) may be used as an alternate for the method of determining 
water herein specified. 
