Field Identification Coarse Grained Soils

Coarse Particle Grade Sizes

Grade name

Boulders Large cobbles Small cobbles

Grade size Sieve no. Comparative size

12" + -- Basketball or larger 6" - 12" -- Cantaloupe to basketball 3" - 6" -- Orange to cantaloupe

Coarse gravel Fine gravel Coarse sand Medium sand Fine sand

3/4" - 3" 1/4" - 3/4" 2.0 - 4.76 mm 0.42 - 2.0 mm 0.074 - 0.42 mm

- Cherry to orange 4 - 3/4" Pea to cherry 10 - 4 Wheat grain to pea 40 - 10 Sugar to wheat grain 200 - 40 Flour to sugar

y "S

Clean gravels

Will not leave a dirt stain on a wet palm.

Wide range in grain sizes and substantial amounts of all intermediate sizes.

M " O 1-

Mostly one size or a range of sizes with some intermediate sizes missing.

Will leave a dirt stain on a wet palm.

Low to nonplastic fines (for identifying fines see Field Identification of Finegrained Soils for ML soils).

Coarsegrained soils1

s e

Plastic fines (for identifying fines see Field Identification of Fine-grained Soils for CL soils).

C C O "T

Clean sands

Will not leave a dirt stain on a wet palm.

Wide range in grain sizes and substantial amounts of all intermediate particle sizes.

Sand and Sandy soils2

S SB

Mostly one size or a range of sizes with some intermediate sizes missing.

Will leave a dirt stain on a wet palm.

Low to nonplastic fines (for identifying fines see Field Identification of Finegrained Soils for ML soils).

S &

Plastic fines (for identifying fines see Field Identification of Fine-grained Soils for CL soils).

V To classify as Coarse-grained, more than half of the material (by weight) must consist of individual grains visible to the naked eye. Individual grains finer than no. 200 sieve cannot be seen with the naked eye nor felt by the fingers. / For visual classification, 1/4-inch size may be used as equivalent to no. 4 sieve.

Copyright ASTM. Reprinted with permission.

Was this article helpful?

0 0
Organic Gardeners Composting

Organic Gardeners Composting

Have you always wanted to grow your own vegetables but didn't know what to do? Here are the best tips on how to become a true and envied organic gardner.

Get My Free Ebook


Post a comment