SAMPLING AND TESTING HIGHWAY MATERIALS. 17 
II. METHOD OF SAMPLING. 
2. Samples of materials of this class shall be of two kinds: 
Class I. Samples of the raw material taken from the natu- 
ral deposits. 
Class II. Samples of the loose material after being mixed 
in place on the roadbed and before consolidation. 
3. Class I samples shall be used for preliminary tests as to the 
suitability of the aggregate subject to admixture of one or more 
ingredients to adjust the composition to the limits set forth in 
the specifications. 
4. The final acceptance of the material as satisfying the speci- 
fications shall be based on Class II samples. 
5. Standard containers. — (I) A three-compartment box of paste- 
board, wood, or metal, outside dimensions 5 by 10 by 10 inches. 
(2) Close-woven bags or sacks of material which do not allow 
sifting out of fine particles, dimensions 6 inches wide by 12 inches 
long. 
6. Labeling. — Each compartment in the box container must labeling 
contain a label showing at what depth the contents were taken, samples. 
The whole sample shall be accompanied by a card, securely at- 
tached thereto, stating date, by whom taken, by whom submitted, 
source of supply, exact location where sample was taken, position 
within the deposit where taken, owner, quantity available, amount 
and character of stripping, if any, whether material from same 
source has been previously used, where, and with what results, 
haul to nearest point on road, average haul to job, character of 
haul, initial cost of material. : 
7. When bag containers are used, one complete sample shall 
comprise three bags, each bag labeled as to depth from which 
the material was taken. 
8. Each bag, or, if preferred, a larger receptacle containing the 
three bags, is to be labeled with the information detailed above. 
9. Method of taking Class I samples. — For each acre or less of ^ ass ' 
area, two samples must be taken, one a local sample and the samples. 
other a composite sample. 
10. The local sample is to be taken near the center of the area. • 
and is intended to represent the vertical average of the material 
at the point. It shall be taken in three layers, each layer 4 inches 
thick, according to the method described as follows : 
(a) The material is to be loosened over a 3 by 3 foot area to 
a specified depth, usually 4 inches. The loose material is to be 
intermixed with a shovel and the sample for one compartment of 
the box container or one of the bags is to be taken therefrom. 
(b) The remaining loose material is to be shoveled out and dis- 
carded. The second layer is to be loosened to equal depth, usually 
4 inches, to be intermixed as before, and a second compartment or 
bag is to filled. The same procedure shall apply to the third layer 
and the filling of the third compartment or bag. 
(c) In exceptionally thick deposits the depth of each layer or 
the number of layers may be increased to cover the entire thick- 
ness of the deposit. 
11. The composite sample is to taken as follows : 
(a) Roughly divide the area to be represented by the sample 
into squares not exceeding 50 feet in size. At the corners of all 
squares loosen a 3 by 3 foot area to a depth of — 6 inches. Thor- 
oughly mix the loose material. Carry an equal amount of the 
material from each such point to a central point and intimately 
mix the various samples. Not less than 200 pounds of material 
must be so mixed. From the center of the pile of mixed material 
fill a container and label for shipment. 
(&) Where the material occurs as a substratum, sink n-> less 
than four 3 by 3 foot pits per acre, or smaller area, to intersect 
6 Depth of 8 inches is suggested, 
67096°— 24 2 
