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UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 347 



Contribution from Office of Public Roads and Rural Engineering 

 LOGAN WALLER PAGE, Director 



Washington, D. C. 



PROFESSIONAL PAPER 



March 17, 1916 



METHODS FOR THE DETERMINATION 



OF THE PHYSICAL PROPERTIES 



OF ROAD-BUILDING ROCK 



By 

 FRANK H. JACKSON, Jr., Assistant Testing Engineer 



CONTENTS 



Introduction 



Physical Properties of Road-Building 



Rock 



Physical Tests of Road Materials: 



Specific Gravity, Weight per Cubic Foot, 

 Water Absorption 



Deval Abrasion Test 



Hardness Test 



Page 

 1 



Page 

 Physical Tests of Road Materials— Contd. : 



Toughness Test 11 



Cementing Value Test 15 



Compression Test 22 



Appendix A — Selection and Shipment of 



Samples 22 



Appendix B— Equipment of Laboratory . 26 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1916 



