METHODS OF SAMPLING AND TESTING HIGHWAY MATERIALS 61 
Sample- -hall be taken from at least 3 inches below the surface and at least 
3 inches from the side of the container or cake or from the center of a cake. 
A clean hatchet may be used if the material is hard enough to shatter and a 
broad stiff putty knife if the material is soft. An auger, or brace and 
% -inch bit. or other suitable means may also be used. When more than 
<>ne package or cake in a lot is sampled, each individual sample shall be not less 
than one-fourth pound in weight. When the lot of material is obviously from 
a single run or batch of the producer all samples from the lot shall be melted 
and thoroughly mixed, and an average sample taken from the combined ma- 
terial for examination. In case more than a single run or batch of the 
producer is present and the batches can be clearly differentiated, a composite 
sample shall be prepared for examination from each batch. Where it is not 
possible to differentiate between the various Par* lie- each sample shall be 
examined separately. 
il>) Liquid materials. —Samples of liquid bituminous materials from barrels or 
drums shall be secured by taking 1 quart of material from packages selected at 
random according to the cube root method described in paragraph (a). When 
the lot of material is obviously from a single run or batch of the producer the 
samples shall be combined and thoroughly mixed and an average sample taken 
from the combined material. In case more than one run or batch is present 
and can be clearly differentiated, a composite sample shall be prepared from 
each batch. Where it is impossible to differentiate between the various 
batches or runs, each sample shall be examined separately. 
13. Solid bituminous materials in crushed fragments or powder, such as 
gil-onite. grahamite. etc., -hall be sampled in accordance with the standard 
method of sampling coal (serial designation D 21 1 of the American Society 
for Testing Materials U). 
41. METHODS OF SAMPLING BITUMINOUS MIXTURES 
A daily sample shall be taken by any of the following method- : 
('/> Samples shall be cut from the finished pavement about 6 to 8 inches 
square and extending full depth of pavement before application of any sealing 
coat which may be used. 
(b) Sample^ of sheet asphalt mixtures shall be taken during preparation of 
the paving mixture from trucks or wagons at the asphalt plant and combined 
into composite sample- of not less than 1 pound each in the following manner : 
These composite samples shall be taken by collecting small quantities at differ- 
ent times from not less than ten and preferably more separate batches, molding 
the portions into the container provided for the purpose. 
In the sampling of bituminous concrete either of the two methods given 
below shall be used in order to obtain a composite sample of not less than 
5 pounds, the amount being dependent on the maximum size of the coarse 
aggregate. Small portions from a number of batches are taken and stored on 
a metal plate until near the end of the day. when the entire mass is reheated, 
care being exercised not to apply too great heat, mixed thoroughly and the 
day's sample selected in -mall portions from this mass. In case of dense 
bituminous-concrete mixtures the samples may be taken by collecting portions 
from one or more batches on a large shovel, thoroughly mixing while s^till 
warm and taking a -mall seoopful which i* placed directly in the carton. This 
operation is to be repeated a< often a> possible, thus representing a maximum 
number of batches. In either of these methods care must be taken to avoid 
segregation of either stone or bituminous mortar. In selecting the portion- 
of the sample, care should be taken to scrape away the top material in the 
load, so as to avoid dust or any segregated unrepresentative mixture. 
(c) Samples shall be taken either at the road or asphalt plant of any 
bituminous mixture which appears defective. 
42. METHODS OF SAMPLING AND TESTING PREMOLDED 
JOINT FILLERS 
One section at least 1 foot long and the full width of the joint shall be 
submitted from each consignment and shall be tested in accordance with the 
following method : 
(a 1 Absorption. — A sample 2 by 6 inches is cut from the joint material in such 
a manner that all edges are freshly cut and weighed. The specimen is then 
