54 
BULLETIN 555, TJ. S. DEPARTMENT OF AGRICULTURE. 
Methods of testing materials: 
Abrasion test (per cent of wear, or French coefficient) stone, stone block, 
and slag 
Abrasion test, suggested for gravel 
Toughness test, stone 
Hardness test, stone and stone block 
Specific gravity and absorption tests, stone 
Weight per cubic foot test, slag 
Mortar strength test, screenings and sand 
Test of size, or grading, of coarse aggregate, stone, slag, and gravel 
Washing test and mechanical analysis, road gravel. 
Elutriation test, sand or fine aggregate 
Mechanical analysis, sand or fine aggregate 
Mechanical analysis and tests of physical properties of semi-gravel. top-soil, 
and sand-clay aggregates 
Specific gravity, road oils, asphalt cements, and tars 
Flash point, road oils and asphalt cements 
Melting point, asphalt cements, refined tars, and tar residues 
Ductility, asphalt cements 
Penetration, asphalt cements 
Float test, road oils, oil residues, and refined tars 
Specific viscosity, road oils and tars. 
Total bitumen, and organic and inorganic matter insoluble in carbon 
disulphide, road oils, asphalt cements, and refined tars 
Bitumen insoluble in naphtha, road oils and asphalt cements 
Volatilization test (loss at 163° C. or other temperature), road oils and 
asphalt cements 
Distillation test, tars 
Fixed carbon, asphalt cements 
Dimethyl sulphate test, tars 
Percentage of residue of penetration, road oils 
Tests of Portland cement 
Tests of Portland cement concrete field samples 
Tests of steel reinforcing rods 
Rattler test, vitrified paving brick 
FORMS FOE TEST RESULTS: 
Rock or slag 
Gravel or sand 
Semi-gravel, top soil, or sand clay 
Petroleum and asphalt products 
Tars. 
Portland cement 
Vitrified paving brick 
Standard methods for sampling: 
Broken stone 
Broken slag 
Stone block 
Gravel 
Sand 
Semi-gravel, top soil, and sand clay. 
Bituminous materials 
Portland cement 
Portland-cement concrete 
Paving brick 
Page. 
30 
30 
31 
31 
31 
32 
32 
32 
32 
32 
33 
33 
36 
36 
36 
36 
36 
36 
36 
36 
36 
36 
36 
36 
36 
36 
37 
37 
37 
37 
38 
39 
40 
41 
42 
43 
44 
45 
45 
46 
47 
47 
48 
49 
50 
51 
51 
