SAMPLING AND TESTING HIGHWAY MATERIALS 
88 
and heated with a blowtorch until fused, or it may be coated with 
a zinc powder paint or aluminum paint. 
9. The number of cubic centimeters of hydrogen measured at 
20° C. (68° F.) multiplied by the factor provided with each ring 
will give the ounces of spelter coating per square foot of actual 
surface on one side of the culvert. By doubling this figure the 
coating in ounces per square foot of sheet surface can be ob- 
tained. The factors for each ring are given in a table accompany- 
ing the apparatus. 
TEST AND INSPECTION OF CORRUGATED METAL 
CULVERT. 
1. Corrugated metal culvert shall he subjeel to inspection at 
the factory, trench, or other point of delivery by the engineer 
or his authorized re] itive. 
Pattern 
i s i 
»?l 
— I 
'Pipe 
bored with 
Yen t Holes. 
'¥--■ 
-*;<|8r 
Pig. Y6. — Mold tor arbitration test bar. 
2. The inspector shall determine the gauge of the metal, in- 
side diameter, depth and spacing of the corrugations, width 
of lap. rivet spacing, and weight per linear foot of the finished 
pipe. He shall also take a sample of the pipe material ap- 
proximately 6 inches wide and the full diameter of the pipe for 
measurement, chemical analysis, and determination of the 
amount of galvanizing or spelter coating. 
: J >. Chemical analysis will be made of all metal culvert pipe to 
determine whether the requirements of the specifications 
quality of the material are met. 
