﻿PHYSICAL TESTS OF ROAD-BUILDING ROCK. 



51 



Table 2. — Results of compression tests of rock, made prior to Jan. 1, 1916- 



WEST VIRGINIA. 



-Continued. 



Serial 

 No. 



Locality. 



County. 



Name. 



Crushing 



strength, 



pounds per 



squareinch. 



5365 









23,350 



5917 









21,300 



5918 





do 





17,450 



5919 





....do 



do 



13, 550 



7475 



Green Spring (east of). 

 .do... 







34,400 

 15,050 



7476 



...do.. . 





6109 









12,400 



9132 







do 



5,420 



9133 



.do .. 



....do 



...do 



5,720 



9134 



...do 



do 



....do 



6,080 



5610 









22,440 



5612 



.do 



....do 





17,910 



5613 



do... 



...do 





14,300 

 29,840 



5614 



....do 



do 





5615 



...do 



do 





19,6.50 



5616 



....do 



do 





24,850 



8447 





Wood 





11,910 













WISCONSIN. 



5523 

 3448 

 8656 



Pebbles 

 Amberg 

 Laruaon 



Fond du Lac 

 Marinette . . . 

 Waukesha. .. 



Dolomite 



Biotite granite 

 Dolomite 



32,600 

 20,000 

 23,020 



Table 3. — General limiting test values. 



Type of construction. 



French 



coefficient 



of wear. 



Toughness. 



Water-bound macadam 



Bituminous macadam 











8 or over.. 



8 or over. 





Water-bound base course 











Granites, gneisses, schists, sandstones, and quartzites should 

 )t, in general, be used in the wearing course of water-bound macadam 

 roads. Shales and slates should never be used in this connection. 

 For further details and explanation of results in this table and 

 also for tests on all materials to January 1, 1916, see U. S. Depart- 

 ment of Agriculture Bulletin 370. 



' Table 4. — Geographical distribution of samples tested from January 1, 1916, to January* 1, 



1922. 



State. 



Number 

 of sam- 

 ples. 



State. 



Number 

 of sam- 

 ples. 





31 

 10 

 55 



3 

 16 

 21 



9 



2 

 12 

 131 



2 





21 







45 



Arkansas 





6 



California 





27 



Colorado 





23 



Connecticut 





3 



Delaware 





46 



district of Columbia 





44 







127 







21 







8 



