Humboldt H-4340 Sand Equivalent Test Set with Case - Manual (Page 3)

Introduction
This method is intended to serve as a rapid field correlation test. The purpose of this
method is to indicate, under standard conditions, the relative proportions of clay-like or
plastic fines and dusts in granular soils and fine aggregates that pass the No. 4
(4.75 mm) sieve. The term "sand equivalent" expresses the concept that most granular
soils and fine aggregates are mixtures of desirable coarse particles, sand, and generally
undesirable clay or plastic fines and dust. This test is not intended to replace either
Method D422 or Method D1140.
Applicable Documents
ASTM Standards:
D422 Particle-Size Analysis of Soils
2
D1140 Test for Amount of Material in Soils finer than the No. 200 75 µm Sieve 2
E11 Specification for Wire-Cloth Sieves for Testing Purposes 3
Summary of Method
A measured volume of soil or fine aggregate and a small quantity of flocculating solution
are poured into a graduated plastic cylinder and are agitated to loosen the clay-like
coatings from the sand particles in the test specimen. The specimen is then "irrigated"
using additional flocculating solution forcing the clay-like material into suspension above
the sand. After a prescribed sedimentation period, the height of floccuiated clay is read
and the height of sand in the cylinder is determined. The sand equivalent is the ratio of
the height of sand to the height of clay times 100.
Significance
This test assigns an empirical value to the relative amount, fineness, and character of
clay-like material present in the test specimen.
A minimum sand equivalent value may be specified to limit the permissible quantity of
clay-like fines in an aggregate.
This test provides a rapid field method for determining changes in the quality of
aggregates during production or placement.
Interferences
Maintain the temperature of the working solution at 72 ± 5° F (22 ± 3° C) during the
performance of this test.
Note 1: If field conditions preclude the maintenance of the temperature range,
frequent referee samples should be submitted to a laboratory where proper
temperature control is possible. It is also possible to establish temperature correction
curves for each material being tested where proper temperature control is not possible.
However, no general correction curve should be utilized for several materials even
within a narrow range of sand equivalent values. Samples that meet the minimum sand
equivalent requirement at a working solution temperature below the recommended
range need not be subject to referee testing.