FOKMS FOR SPECIFICATIONS, ETC., FOE ROAD MATERIALS. 



19 



General. 



Grading. 



SPECIFICATION FOR SAND FOR SHEET ASPHALT. 



The sand shall be composed of sound, durable particles, free 

 from a coating of clay or loam. 



When tested by means of laboratory sieves, it shall meet the 

 following requirements : 



Per cent. 



Passing 10-mesh sieve not less than 



Passing 10-mesh and retained on 40-mesh 



sieve to 



Passing 40-mesh and retained on 80-mesh 



sieve to 



Passing 80-mesh and retained on 200-mesh 



sieve to :_ 



Passing 200-mesh sieve . to 



The sand shall be sampled for grading in accordance with 



the method described on page , paragraphs , of these 



specifications ; and tests of grading shall be made in accordance 



with the method described or referred to on page of these 



specifications, test No. 



Note. — It is recommended that volumetric analyses be reported 

 by the laboratory to facilitate field control. 



SPECIFICATION FOR SAND FOR FINE AGGREGATE FOR PORTLAND-CEMENT 



CONCRETE BASE. 



Methods of 

 sampl i n g and 

 grading. 



The sand shall consist of clean, hard, durable, uncoated par- 

 ticles, preferably siliceous, free from lumps of clay and all organic 

 matter. 



It shall be well graded from coarse to fine and, when tested by 

 means of laboratory screens and sieves, shall meet the follow- 

 ing requirements: Percent. 



Passing 1/4-inch screen 100 



Passing 20-mesh and retained on 50-mesh 



sieve . to 



*Passing 50-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 proportion 



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. 



* It is recommended that the amount passing the 50-mesh sieve be 

 limited to 30 per cent, or less, if practicable. 



t It is recommended that the minimum strength ratio for this purpose 

 be 70 per cent, or greater, if possible under existing conditions ; and 

 that where sands giving a 70 per cent strength ratio are not available 

 the proportion of cement be increased so as to give that percentage. 



General. 



Grading. 



Mortar 

 strength test. 



