24 BULLETIN 555, U. S. DEPARTMENT OF AGRICULTURE. 



5. Loss at 163° C. (325° F.), 5 hours, not more than 



per cent, 

 (a) Penetration of residue at 25°C. (77°F.), 100 g., 5 

 sec, not less than 



6. Total bitumen (soluble in carbon disulphide) not less 



than per cent. 



(a) Organic matter insoluble, not more than 



per cent. 



(b) Inorganic matter insoluble, not more than 



per cent. 



(or to per cent). 



Method of test- Tests of the physical and chemical properties of the asphalt 



iug. 



cement shall be made in accordance with the methods described, 



or referred to on page of these specifications, tests 



Nos. . 



Notes. — (1) In some instances it may be considered desirable 

 to include an 86° B. naphtha solubility clause, in which case the 

 wording should be: Per cent of total bitumen insoluble in 86° B. 

 naphtha, to per cent. 



(2) In some instances it may be considered desirable to in- 

 clude a fixed carbon requirement, in which case the wording 

 should be : Fixed carbon, to per cent. 



(3) In certain cases the inclusion of all the tests listed or noted 

 may not be desirable, but it is necessary to use certain combina- 

 tions of the tests in order to secure a material suitable for a 

 specified purpose. 



SPECIFICATION FOE TARS FOR COLD APPLICATION. 



General. The tar shall be homogeneous. 



Physical and It shall meet the following requirements: 

 chemical proper- L Specific ^.^ 25 o /25 o Q (77 ° /77 o p }> tQ 



2. Specific viscosity at ° 0.* ( ° F.), to 



3. Total distillate by weight : 



I'er cent. 



To 170° C. (338° F.), not more than 



To 235° C. (455° F.), not more than 



To 270° C. (518° F.), not more than 



To 300° C. (572° F.), not more than 



(c) Melting point of residue ° C. ( ° F.), 



to ° C°. ( ° F.). 



4. Total bitumen (soluble in carbon disulphide, to 



per cent. 



Methods of 



testing. Tests of the physical and chemical properties of the tar shall 

 be made in accordance with the methods described, or referred 

 to, on page of these specifications, tests Nos. 



Notes. — (1) In some instances it may be desirable to insert a 

 specific gravity of distillate requirement after the melting point 

 requirement, in which case the wording should be: (b) Specific 

 gravity of total distillate 25V25° C. (77°/77° F.), to 



(2) In some instances it may be considered desirable to insert 

 a requirement for solubility in dimethyl sulphate of one or more 

 fractions of the distillate. In such cases insert as follows: 



Solubilitv in dimethyl sulphate of distillate from ° C. 



( ° F.) to ° C. ( ° F.), to per 



cent. 



* It is recommended that the viscosity determination be made at 

 25° C. (77° F.) or 40° C. (104° F.), according to the nature of the 

 product desired. 



