SPECIFICATIONS FOR NONBITUMINOUS ROAD MATERIALS. 3 
a means toward standardizing not only specifications for broken stone 
but also plant practice in the production of broken stone for highway 
work. 
The forms of specification adopted for broken stone as well as other 
nonbituminous road materials are, in general, those recommended 
by the First Conference of State Highway Testing Engineers and 
Chemists.t_ Following each specification is a brief descriptive para- 
graph, stating the general conditions governing its uses and what 
modifications may in certain instances be made. More detailed in- 
formation and advice relative to methods of construction may be 
obtained upon application to the Bureau of Public Roads. 
- It is realized that all classes and types of nonbituminous road ma- 
terials have not been covered, and it is intended to add to the num- 
ber of these specifications from time to time. For the convenience of 
engineers, and in order to make this bulletin complete in itself, the 
methods of test to which reference is made in the specifications, and 
directions for sampling, are given in an appendix. 
TaBLE I1.—Relation of commercial revolving screens to laboratory screen 
requirements for broken stone. 
Revolving screens. 
Type of road. 3-inch. | 2-inch. | 1-inch. | 4-inch. | 41-inch. 
-Per cent passing laboratory screen of 
same size. 
Water-bound: | 
IBOttOMUCOUTSC Seo tie ee ona oe ents sia ine sais bites Slsraviaists 95+ lis eit | ee ay ag aren eel (ee a 
DOD COIS. ss so sun sees obdasndasesSsSacob Iso -seeSsassbo5ssollecesocae 95+ VOSS Pete eae Sees 
SORTA. esac csebbb ob Sabsededoeosboscsnccesebsadesactcodloacstoca|sacouqes WORE lIbeSecaae 40-80 
or 
IB ASClOMDOLNICOUTSCS aetna iee es ee ae See See Cie el eedanos [paar |esiacises| ame a ae 
SORES. = sash ese edaseen eps Se soeddusecbdeeacooosaced|aesoonos)|Ssescdor JERR leooconas 40-80 
Cover for bituminous surface treatment: | 
(COPR® GMD 4. ase ned SSR no sad bsasocas so Soa aesaceegseenc [Pe aetgos||oSSeceHe GRE sesneeee 15— 
or 
THAWED SS 5 Sete RSA Re Se Bakar Bee GORE Oe ES SOD SE Ia eee |i See Ee | estas cate leet ein 85+ 15— 
Bituminous macadam: 
IBOFLOMUCONTSC ah seein ses enc ats eh poe = eis ge emo seen 95+-+ Tye MA case oo Pal [acetic a (Benet a 
Mop Coutses-e-es—4-—e Doognstebssssdods cb oqeedeeusebuoSusoclsesonace 95+ SS ree AO ect ae 
(OS. 25 ladhtssessodissessccdseosshe sees 5ees Ao SEE oon |eee coca: fon Soe eee tore tcoegssas 15— 
SCTSCMING Serpe een eters ae Soe ce ee peace oe ace Sal fess cee Seeaaaoe CO leemenae 40-80 
Bituminous macadam: 
UVGGin ie OU UNO Got. 5" Shite be Hees bee Seeioe Depboo se be oan eso nemo arse | 95+ Gl eed eco eee 
CINDS: 22 568 este Soc oe tues easel eee docea oer cep aeeeues bass lSeossees||peseosne ier oa se ee 15— 
Bituminous concrete: 
ONGESIZEISLONCmerems sete ies to oe eS ee eee ee Se eet ella se ele OB AeA lsneeesee 15— 
Qlith Sesseneso conse ao Be ie Je Sepa Sees E exe ieee setae Faeyr meee [see aa ee eee 95+ 15 
Graded bituminous concrete: 
Coarse aggregate.....---.-.-...-- pedis wana estes alee oe Bee spall eapeeteras | yaya oe Ob ate 2 menecs 8 15— 
C@hipsesee ee eee ee eee ee ta Fe Bes EN ree eg Ni Sata ise fae 95-+- 15— 
Bituminous concrete (Topeka): 
IBTOKCINSLONG acest tee ae eee som ine ce oo een Boa eR Mh e se ee eos eS 95+ 80— 
Sheet asphalt: 
ITI ORIGLONG eer se ye eas Senate eee ee here uals ocala oe esha. Fa ie eee eae en ee 
Cement concrete pavement: 
WOATSOIAL STOP ATC seta ae oe ate ie ow ascicpiainys wise yale awl asia oars fe ose Ue PE ae oeacoe ease ne 15— 
Cement concrete base: 
Woarsciaceresabes core saat eat at seeiscleias eee ears. 5 Hotes BS. Oeste eel laren a Fees 15— 
