pe STATES DEPARTMENT OF PORICULIURE 
4, BULLETIN No. 314 
Contribution from Cffiice of Public Roads and Rurai Engineering 
LOGAN WALLER PAGE, Director 
Washington, D.C. | PROFESSIONAL PAPER. December 10, 1915 
METHODS FOR THE EXAMINATION OF BITUMI- 
NOUS ROAD MATERIALS. 
By Prtvosr Huspsarp, Chemical Engineer, and 
CHARLES 8S. REEVE, Chemist. 
CONTENTS. 
Page. | Page. 
Classification of materials.................... 2 | Bitumen soluble in carbon disulphide -...... 25 
Scheme of examination ...............2.-2--- 2 | Bitumen insoluble in paraffin naphtha...._. 28 
Specific gravity determination. ............. 4 | Bitumen insoluble in carbon tetrachloride. . - 30 
Specific viscesity determination............. Thea Rabo opel clove) alanine atm pm eee Rael 30 
TOIGER WSSU S SSS Re is all NET Se Oh rare timsealers 25 aoa se) iene Mi WV Mae one 32 
Pe Me vnatiOmiteSG espanol Mae eens ce Serene 11 | Extraction of bituminous aggregates ...._.._. 35 
Melting point determination............-... 14 | Grading the mineral aggregate ............-- 38 
Flash and burning points..._..-............ 16 | Voids in the mineral aggregate .........._... 29 
Wolabilizatitonl teshe ses. teens oe ee eee L9G SBituminousemulsions!: oes soe ee 4] 
IDNSUlE ONT Wesiiee aaouce = aH oe Cae aaan Rae asar Pay Walle aVeN oN a sy a6 Lb, tte eum tcres Rica c anit ca ning sntiy ool aT AA Bean 43 
Dimethyl sulphate test ...............-....- 25} 
INTRODUCTION. 
This bulletin is the first revision of Office of Public Roads Bulletin 
No. 38, which was issued July 27, 1911. Its object is to present a 
description of methods now in use by the Office of Public Roads and 
Rural Engimeering for the examination of bituminous road niaterials 
in such form that, with a little practice and proper equipment, such 
examinationsmay bemadebyany intelligent person. Thevarious tests 
have, therefore, been described rather more in detail than would be 
necessary if they were intended for the use of chemists only, and illus- 
trations of practically all of the apparatus required have also been 
included. 
Since the publication of Bulletin No. 38 considerable progress has 
been made in the standardization of methods of examining bituminous 
road materials. Many of the methods described in Bulletin No. 38 
have been generally adopted. Certain of these methods have, how- 
ever, been improved during the past four years and the constant 
demand for this bulletin has led to its present revision. The 
changes and additions noted below are the result of investigations 
conducted in the laboratories of the office and of cooperative work 
with certain technical societies. 
8016°—Bull. 314151 
