24 
General. 
Methods of 
Testing. 
BULLETIN 704, U. S. DEPARTMENT OF AGRICULTURE. 
SAND FOR GROUTING, 
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-_________ AP SC SBT Is REN ct p= | 100 
Passing a7 20=MeshsSieven Ot eleSS tin arte ne eee en we 80 
iPassine va 100-mesh sieves not) moresthanes se ee ee eee 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. 
Tests of the physical properties of the brick and sand shall be made in 
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. _ 
38. 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 brick wearing course, and sand cushion for 
two sizes of brick. 
The sand cushion or sand cement cushion should preferably be 
placed upon a concrete foundation to a depth after rolling of not 
over 13 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. 
