SPECIFICATIONS FOR NONBITUMINOUS BROAD MATERIALS. 
That portion of the product of the crusher which, when tested by Bottom Course 
means of laboratory screens, will meet the following requirements: Stone. 
Per cent. 
RASSin gee in Che sereen. Not Wess) than= =) ie as ee ee 95 
MOTales PASSING Ras LC SCRE C Mera nous ts aie ee een a PAY RO) (5s 
Retained on 2-inch-sereen} not less’ than2 2-2 2]. Se 85 
Tests of the physical properties of the rock and of the sizes of broken- wae Os 
stone products shall be made in accordance with the following methods: 
1. French coefficient of wear, U. S. Department of Agriculture Bulletin 
347, p. 5. 
2. Size, U. S. Department of Agriculture Bulletin 555, p, 32. 
This specification is intended to cover stone to be used in the 
construction of a water-bound broken-stone base, and a pitumi- 
nous broken-stone wearing course constructed by the penetration 
method. If the base is not to be water bound, the use of granite, 
gneiss, Sandstone, or quartzite may be allowed, provided the ma- 
terial otherwise meets the specifications. Practically the entire 
output of an ordinary portable crushing outfit will be utilized if 
a bottom course filled with screenings is constructed 5 inches 
thick and a top course from 2% to 3 inches thick. The chips should 
be used to fill the surface voids in the top course after the first 
application of bituminous material has peen made and also as a 
cover for the second application or seal coat. Such roads may be 
maintained with surface treatments of bituminous material, cov- 
ered with material conforming to Specification RS-1 or RS-2. 
SPECIFICATION RB—2. 
Broken Stone for Bituminous Macadam Wearing Course. 
The broken stone shall consist of angular fragments of rock, excluding 
schist, shale, and slate, 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 requirement: Physical 
Hrenchacochicientaot wears Notslessathan 22 an eae ee T mEOnertics. 
That portion of the product of the crusher which, when tested by means Chips. 
of laboratory screens, will meet the following requirements: 
General. 
Per cent. 
RASS saci che screens NOC Less) (hans. seen Se eee eee 95 
Retainedvone=-michescreen, not less) than] voll Seek ei ots Pe ee 85 
That portion of the product of the crusher which, when tested by means Coarse 
of laboratory screens, will meet the following requirements: Stone. 
Per cent. 
IBASSiInoE Im GheSCLeen aon OG JLOSS at oyIt ee 95 
NOME ASSIMoer ks lINCn SCLCCME ee ss a es a Day Koy: OS 
Retaineasens1-ineh screen. not. less: than _-— 22) = ee | 85 
Tests of the physical properties of the rock and of the sizes of broken Methods of 
stone products shall be made in accordance with the following methods: Testing. 
1. French coefficient of wear, U. S. Department of Agriculture Bulletin 
SA, Os 
2, Size, U. S. Department of Agriculture Bulletin 555, p. 32. 
This specification covers stone to be used in the construction of 
a bituminous broken-stone wearing course in which the bituminous 
material is applied by the penetration method. The maximum size 
