12 BULLETIN 940, U. S. DEPARTMENT OE AGRICULTURE. 



determined on air-dry material. When the aggregate contains an appreciable amount 

 of moisture the percentage of water by weight shall be determined and recorded. 



(2) Fill the measure one-third full, puddle with 25 to 30 strokes from a ^-inch 

 round steel bar 20 inches long, pointed at the lower end. Continue filling and 

 puddling in like manner until the measure is full, then strike off the top by a rolling 

 motion with the bar. Determine the weight of the contents of the measure and 

 calculate the weight in pounds per cubic foot. 



9. SIEVE ANALYSIS OF BROKEN STONE, GRAVEL, PEBBLES OR BROKEN 



SLAG. 



(A. S. T. M. Standard Method, D 18-16, slightly modified.) 



The method shall consist of (1) drying at not over 110° C. (230° F.) to a constant 

 weight a sample weighing in pounds six times the diameter in inches of the largest 

 holes required; (2) passing the sample through such of the following size screens 

 having circular openings as are required or called for by the specifications, screens 

 to be used in the order named: 8.89 cm. (3$ inches), 7.62 cm. (3 inches), 6.35 cm. 

 (2\ inches), 5.08 cm. (2 inches), 3.81 cm. (l£ inches), 3.18 cm. (l\ inches), 2.54 cm. 

 (1 inch), 1.90 cm. (f inch), 1.27 cm. (\ inch), and 0.64 cm. (\ inch); (3) determining 

 the percentage by weight retained on each screen; and recording the mechanical 

 analysis in the following manner: 



Per cent. 



0.64 cm. (\ inch) screen 



Passing 1.27 cm. [\ inch) screen and retained on a 0.64 cm. (\ inch) screen 



Passing 1 .90 cm. (f inch) screen and retained on a 1.27 cm. (J inch) screen 



Passing 2.54 cm. (1 inch) screen and retained on a 1.90 cm. (f inch) screen 



100. 00 



10. SIEVE ANALYSIS OF SAND OR FINE AGGREGATE. 



(A. S. T. M. Standard, Serial Designation: D 7-18, slightly modified.) 



The method shall consist of (1) drying at not over 110° C. (230° F.) to a constant 

 weight a sample weighing not less than 100 grams and not more than 500 grams; (2) 

 passing the sample through each of the mesh sieves 2 (American Society for Testing 

 Materials standard sieves) specified in Table 1; (3) determining the percentage by 

 weight retained on each sieve, the sifting being continued on each sieve until less 

 than 1 per cent of the weight retained on each sieve shall pass through the sieve during 

 the last minute of sifting; and (4) recording the mechanical analysis in the following 



manner: 



Per cent. 



Passing 200-mesh sieve 



Passing 100-mesh sieve and retained on a 200-mesh sieve 



Passing 80-mesh sieve and retained on a 100-mesh sieve 



Passing 50-mesh sieve and retained on an 80-mesh sieve 



100.00 



2 The order in which the sieves are to be used in the process of sifting is immaterial and shall he left 

 optional; but in reporting results the order in which the sieves have been used :;hall be stated. 



