METHODS OF SAMPLING AXD TESTING HIGHWAY MATERIALS 37 
2. The sample shall be dried to constant weight at a temperature not exceed- 
ing 110° C. (230° F.). 
3 (a) The sieves shall be of square-mesh wire cloth and shall be mounted on 
substantial frames constructed in a manner that will prevent loss of material 
during sieving. 
(&) The size of wire and sieve openings shall conform to the requirements 
given in Table 3. 
4. (a) The sample shall be separated into a series of sizes by means of the 
sieves specified in section 3. Sieving shall be continued until not more than 1 
per cent by weight of the residue passes any sieve during one minute. 
( 1) » Each size shall be weighed on a balance or scale which is sensitive to 
0.001 of the weight of the test sample. 
i c | The percentage by weight of the total sample which is finer than each 
of the sieves shall be computed. 
5. (a) The percentages in sieve analysis shall be reported to the nearest 
whole number. 
( 6 ) If more than 15 per cent of a fine aggregate is coarser than the Xo. 4 
(4,760 microns) sieve, or more than 15 per cent of a coarse aggregate is finer 
than the Xo. 4 (4.760 microns) sieve, the sieve analysis of the portions finer and 
coarser than this sieve shall be reported separately. 
28. METHOD OF MECHANICAL ANALYSIS OF SAND OR 
OTHER FINE HIGHWAY MATERIAL 
(A. S. T. M. standard method ( ', 
serial designation D 7-21 
P. 1) 
except as indicated. See 
1. A representative test sample of the aggregate weighing [50 grams] not less 
than 100 gram* shall be taken. 
Note. — When sarnies contain more than 2 per cent silt it is recommended Hint tiii 
(hitriation test It made prior to and on the same sample a* the sieve o,n<dysis. 
2. The sample shall be dried to constant weight at a temperature not 
ceeding 110° C. (230° F.). 
3. (a) The sample shall be passed through each of the standard sieves speci- 
fied in Table 4. 
T.-ble 4. — Requirement* for sieve openings and- wire diameters with permissiole 
rariations 1 
: ieve opening 
Wire diameter 
e-ignation. United 
Stater- standard sieve series 
Milli- 
meters 
Inches 
Milli- 
meters 
10 . 2.00 0.0787 76 
20 .84 .0331 .42 
30 .59 .0232 > .33 
40 .42 .01*o .25 
.50 .297 .0117 .188 
gO .177 .0070 .119 
100 .149 .0059 .102 
200 .074 .0029 .053 
Inches 
Toler- 
, ance in 
1 average 
i opening 
Tolerance on I 
wire diameter j Toler- 
j ance in 
maxi- 
mum 
Under 
0.0299 i 
.0165 I 
.0130 I 
.0098 ! 
.0074 
.0047 
.0040 
.0021 
: Per cent 
±3 
±5 
±5 
±5 
±6 
±6 
±6 
±8 
Per cent 
15 
15 
15 
15 
15 
15 
15 
15 
Over opening 
Per cent 
30 
30 
30 
30 
35 
35 
35 
35 
Per cent 
10 
25 
25 
25 
40 
40 
40 
! The dimensions and tolerances for these sieves conform to the requirements of the standard specifica- 
tions for sieves for testing uurposes (serial designation E 11) of the American Societv for Testing Materials 
(3, p. 789). 
2 The order in which the sieves are to be used in the process of sieving is immaterial and shall be left 
optional, but in reporting results the order in which the sieves have been used shall be staled. 
I b j The percentage by weight retained on each sieve shall be determined 
and the sieving on each sieve shall be continued until less than 1 per cent of the 
weight retained on each sieve shall pass through the sieve during the last 
minute of sieving. 
