UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 314 



Contribution from Office of Public Roads and Rural Engineering 

 LOGAN WALLER PAGE, Director 



Washington, D. C. 



PROFESSIONAL PAPER 



December 10, 1915 



METHODS FOR THE EXAMINATION OF 

 BITUMINOUS ROAD MATERIALS 



By 



PREVOST HUBBARD, Chemical Engineer, and 

 CHARLES S. REEVE, Chemist 



CONTENTS 



Page 



Classification of Materials 2 



Scheme of Examination 2 



Specific Gravity Determination .... 4 



Specific Viscosity Determination ... 7 



Float Test 9 



Penetration Test 11 



Melting Point Determination 14 



Flash and Burning Points 16 



Volatilization Test 19 



Distillation Test 21 



Dimethyl Sulphate Test 25 



Page 

 Bitumen Soluble in Carbon Dlsulphide . 25 

 Bitumen Insoluble in Paraffin Naphtha . 28 

 Bitumen Insoluble In Carbon Tetra- 

 chloride 30 



Fixed Carbon SO 



Paraffin Scale 32 



Extraction of Bituminous Aggregates . . 35 



Grading the Mineral Aggregate .... 38 



Voids in the Mineral Aggregate .... 39 



Bituminous Emulsions 41 



Appendix 43 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1915 



