BULLETIN 555, U. S. DEPARTMENT OF AGRICULTURE. 
Physical prop- 
erties. 
Chips or No. 
. stone. 
Top course or 
No. atone. 
Bottom course 
or No. stone. 
Method of sani- 
liline. 
Methods of 
testing. 
The stone shall meet the following requirements: 
Per cent of wear not more than 
(or French coefficient not less than ) 
♦Toughness not less than 
*Hardness not less than 
♦Absorption not more than % 
That portion of the product of the crusher which, when tested 
by means of laboratory screens, will meet the following require- 
ments : 
Per cent. 
Passing inch screen 100 
Total passing inch screen to 
Retained on inch screen 100 
That portion of the product of the crusher which, when tested 
by means of laboratory screens, will meet the following require- 
ments : 
Per cent. 
Passing inch screen __ 7 100 
Total passing inch screen to 
Retained on inch screen 100 
That portion of the product of the crusher which, when tested 
by means of laboratory screens, will meet the following require- 
ments : 
Per cent. 
Passing inch screen 100 
Total passing inch screen to 
Retained on inch screen 100 
Stone shall be sampled for quality and size in accordance with 
the method described on page , paragraphs , of these 
specifications. 
Tests of the physical properties and sizes of the stone shall be 
made in accordance with the methods described or referred to on 
pages of these specifications, tests Nos. 
SPECIFICATION FOR BROKEN STONE AGGREGATE FOR LARGE AGGREGATE 
BITUMINOUS CONCRETE. 
General. 
Physical prop- 
erties. 
Grading. 
The broken stone aggregate shall consist of angular fragments of 
._ _ _ ( 3?_ ser * _t^?_ e _ s _ ^l 1 . ^^ 1 . 6 '_ » of uniform quality throughout, free 
from thin or elongated pieces, soft or disintegrated stone, dirt, or 
other objectionable matter, occurring either free or as a coating 
on the stone. 
The stone shall meet the following requirements: 
Per cent of wear not more than 
(or French coefficient not less than .) 
♦Hardness not less than 
♦Toughness not less than 
♦Absorption not more than % 
The broken stone aggregate, when tested by means of laboratory 
screens, shall meet the following requirements : 
* Tests recommended by the conference which it may be desirable to 
omit in some instances. 
