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BULLETIN 704^ U. S. DEPABTMENT OF AGRICULTUEE. 



SAND FOR GROUTING. 



General. The sand shall consist of clean, hard, durable, uncoated-stone particles, 



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 following requirements : 



Per cent. 



Passing a 10-mesh sieve 100 



Passing a 20-mesh sieve, not less than 80 



Passing a 100-mesh sieve, not more than 10 



Not more than 5 per cent by weight shall be removed by the elutri- 

 ation 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 meth- 

 ods 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 75 per cent of that 

 developed in the same time by mortar of the same proportions and con- 

 sistency, 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. 

 Methods of Tests of the physical properties of the brick and sand shall be made in 



Testing. accordance with the following methods : 



1. Rattler Test, A. S. T. M. Standard, C7-15. 



2. Grading of Sand, U. S. Department of Agriculture Bulletin 555, p. 33. 



3. Elutriation Test for Sand, U. S. Depuartment of Agriculture Bulle- 



tin 555, p. 32. 



4. Mortar Tensile Strength Test for Sand, A. S. T. M. Standard C9-17. 



These specifications cover vitrified paving brick, cushion sand, 

 and grouting sand for bricl£ wearing course, and sand cushion for 

 two sizes of brick. 



The sand cushion or sand cement cushion sliould preferably be 

 placed upon a concrete foundation to a depth after rolling of not 

 over 1^ inches. This cushion should be shaped to the desired cross 

 section of the finished wearing course before .placing the brick. 

 After laying and rolling the brick, the joints are filled with a grout 

 composed of equal parts of cement and grouting sand reduced with 

 water to a creamy consistency. If desired, a bituminous mastic or 

 a bituminous filler may be poured hot into the joints. In the lat- 

 ter case, the requirement for grouting sand and all reference there- 

 to should be eliminated from the specifications. 



