FORMS FOE SPECIFICATIONS, ETC., FOR ROAD MATERIALS. 
21 
It shall be well graded from coarse to fine and, when tested 
by means of laboratory screens, shall meet the following re- 
quirements : 
Per cent. 
Passing * mesh sieve not less than t 
Passing 100-mesh sieve not more than 
Not more than per cent by weight shall be removed by 
the elutriation test. 
When the sand is mixed with Portland cement in the propor- 
tions of 1 part of cement to 3 parts of sand by weight, according 
to standard methods of making 1 :3 mortar briquets, the resulting 
mortar at the age of 7 and 28 days shall have a tensile strength 
of at least t per cent of that developed in the same time 
by mortar of the same proportions and consistency, made of the 
same cement and Ottawa sand. 
Preliminary acceptance samples shall be subjected to both 7 
and 28 day tests, and acceptance based thereupon. Samples tested 
during the progress of the work will be accepted on the basis of 
the 7-day test. 
The sand shall be sampled in accordance with the method de- 
scribed on page , paragraphs , of these specifications ; 
and the grading shall be determined in accordance with the 
methods described, or referred to, on page of these speci- 
fications, tests Nos. 
Note. — It is recommended that volumetric analyses be reported 
by the laboratory to facilitate field control. 
SPECIFICATION FOR SAND FOR CUSHION. 
The sand shall pass a inch laboratory screen, and not 
less than per cent shall pass a 20-mesh sieve. The ma- 
terial removed by the elutriation test, consisting chiefly of clay 
and loam, shall not exceed per cent by weight. 
The sand shall be sampled in accordance with the method de- 
scribed on page , paragraphs , of these specifications ; 
and the grading shall be determined in accordance with the 
methods described, or referred to, on pages of these speci- 
fications, tests Nos. 
Grading. 
Note. — It is recommended that volumetric analyses be reported 
by the laboratory to facilitate field control. 
SPECIFICATION FOR MINERAL FILLER. 
Mortar 
strength test. 
Methods of 
sampl i n g and 
grading. 
Grading. 
Methods of 
sampl i n g and 
testing. 
The mineral filler shall consist of (^^jAAyP^^P^We) 
It shall be free from foreign or other objectionable material and 
when tested by means of laboratory sieves shall meet the follow- 
ing requirements : Per cent. 
Passing -mesh sieve 100 
Passing -mesh sieve not less than 
General. 
* It is recommended that a 10-mesh sieve be specified. 
f Ninety-five per cent is recommended for this purpose. 
t It is recommended that 65 per cent be the minimum allowable 
strength ratio, and that in localities where practicable a higher strength 
ratio be specified. 
