80 
BULLETIN 1216, U. S. DEPARTMENT OF AGRICULTURE. 
dressed. No frame slmll come in contact with the pipe during 
the test. A strip of cloth may. if desired, be attached to the 
inside of the upper frame on each side, along the lower edge, to 
prevent the escape of sand between tbe frame and the pipe. 
10. Pieces of the crushed pipe may be used as specimens in 
making the absorption test and freezing and thawing test. 
\ 
(B) Absorption Test. 
Absorption 11, The specimens shall be sound pieces with all edges broken, 
test. and may be from pipes broken in the crushing or other tests. 
They shall be from 12 to 20 square inches in area and shall be as 
nearly square as they can be readily prepared. They shall be 
free from observable cracks, fissures, laminations, or shattered 
edges. 
12. Preparatory to the absorption test the specimen shall first 
be weighed and then dried in a drier or oven at a temperature of 
not less than 110° C. (230° F.) for not less than three hours. 
After removal from the drier the specimen shall be allowed to 
cool in dry air to a temperature of 20° to 25° C. ( 68° to 77° F.) 
and then reweighed. 
If the specimen is comparatively dry when taken and the sec- 
ond weight closely agrees with the first, it shall be considered 
dry. If the specimen is wet when taken, it shall be placed in the 
drier for a drying treatment of two hours and reweighed. If the 
first weight checks the second, the specimen shall be considered 
dry. In case of doubt the specimen shall be redried for two-hour 
periods until check weights are obtained. 
13. The balance used shall be sensitive to 0.5 gram when loaded 
with 1 kilogram, and weighings shall be read to the nearest 
gram. When other than metric weights are used, the same degree 
of accuracy shall be obtained. 
14. The specimen after final drying, cooling, and weighing shall 
be placed with other similar specimens in a suitable wire recep- 
tacle, packed tightly enough to prevent jostling, covered with dis- 
tilled water or rain water, raised to the boiling point and boiled 
for five hours, and then cooled in water to a final temperature of 
10° to 15° C. (50 to 59° F.). 
15. The specimen shall be allowed to drain for one minute and. 
the superficial moisture having been removed by towel or blotting 
paper, placed upon the balance. 
16. The test result shall be calculated as percentage of the 
initial dry weight. 
17. Three specimens shall be tested of each pipe broken in the 
crushing test. 
18. The results shall be reported separately for each individual 
specimen, together with the mean for all the specimens from the 
same shipment of pipe. 
19. Each specimen shall be marked so that it may be identified 
with the pipe used in the crushing test from which the specimen 
was taken. The marking shall be applied so that the pigment 
used shall not cover more than 1 per cent of the total superficial 
area of the specimen. 
(C) Freezing and Thawing Tests. 
Freezing and 20. The test specimens employed in making the freezing and 
thawing tests, thawing test shall be another set of three selected as specified 
in section 11. 
21. The specimens shall be dried as specified in section 12. 
22. The same scales and weights as are specified in section 
13 for the absorption test or others of equivalent sensitiveness 
and accuracy shall be employed for the weighings required in 
the freezing and thawing test. The same procedure in weigh- 
ing and reweighing as specified in section 13 shall be used. 
