22 



BULLETIN 555, U. S. DEPARTMENT OP AGRICULTURE. 



Methods of 

 samp li 11 g and 

 grading. 



The mineral filler shall be sampled for quality and grading in 

 accordance with the method described on page , para- 

 graph , of these specifications ; and the grading shall 



be determined in accordance with the method described or re- 

 ferred to on page of these specifications, test No. 



SPECIFICATION FOR ROAD OILS FOR COLD APPLICATION. 



General. 



Physical and 

 chemical proper- 

 ties. 



Methods ef 

 testing. 



The road oil shall be homogeneous and free from water. 

 It shall meet the following requirements : 



1. Specific gravity 25°/25° C. (77°/77° F.), to 



2. Flash point, not less than ° C. ( F.). 



[or ° C, ( ° F.) to ° C. ( ° F.)*] 



3. Specific viscosity at ° C.t ( ° F.), to 



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



(or to per cent.*) 



t{a) Float test of residue at 50° C. (122° F.), 



to sec. 



5. Total bitumen (soluble in carbon disulphide) not less than 



per cent. 



6. Per cent of total bitumen insoluble in 86° B. naphtha, 



to 



Tests of the physical and chemical properties of the road oil 

 shall be made in accordance with the methods described or re- 

 ferred to on page of these specifications, tests Nos. 



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

 to include a requirement for loss at 105° C. (221° F.), in which 

 case the wording should be: Loss at 105° C. (221° F. ), 5 hours, 

 not less than per cent. 



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

 clude a requirement for the percentage of residue of pene- 

 tration, in which case the wording should be: Percentage of 

 residue of penetration, to 



(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 FOR ROAD OILS FOR HOT APPLICATION. 



General. The road oil shall be homogeneous, free from water, and shall 



not foam when heated to ° C. ( '. ° F.). 



Physical and It shall meet the following requirements: 

 chemical proper- ^ gpecific ^.^ ^ /25 „ c (77 ° /77 ° K)> to 



* In cases where the presence of a volatile or light flux is desired the 

 second form of the flash-point requirement and of the loss at 163° C. 

 requirement should be used ; in all other cases the first form of require- 

 ment is applicable. 



t 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. 



% In case the oil is to be used as a dust layer only, this requirement 

 Is to be omitted. 



