903CLASSIFICATION OF SOILS

903.01Definitions

All soils shall be tested and classi fied in accordance w ith AASHTO M 145, and in accordance with the grain-size classification procedure as follows:

Classification Definition Boulders Retained on 3 in. (75 mm) sieve Gravel 3 in. (75 mm) to No. 10 (2.0 mm) sieve Coarse Sand No. 10 (2.0 mm) to No. 40 (425 μm) sieve Fine Sand No. 40 (425 μm) to No. 200 (75 μm) sieve Silt 0.075 to 0.002 mm Clay Smaller than 0.002 mm Colloids Smaller than 0.001 mm

903.02Soils Having 0% to 19% Retained on No. 10 (2.00 mm) Sieve

These soils shall be classified as follows:

903.02

Classification Sand and Gravel, % Silt, % Clay, % Sand 80 – 100 0 – 20 0 – 20 Sandy Loam 50 – 80 0 – 50 0 – 20 Loam 30 – 50 30 – 50 0 – 20 Silty Loam 0 – 50 50 – 80 0 – 20 Silt 0 – 20 80 – 100 0 – 20 Sandy Clay Loam 50 – 80 0 – 30 20 – 30 Clay Loam 20 – 50 20 – 50 20 – 30 Silty Clay Loam 0 – 30 50 – 80 20 – 30 Sandy Clay 50 – 70 0 – 20 30 – 50 Silty Clay 0 –20 50 – 70 30 – 50 Clay 0 – 50 0 – 50 30 – 100

903.03Soils Having 20% or More Retained on No 10 (2.00 mm) Sieve and

More Than 20% Passing No. 200 (75 μm) Sieve These soils shall be classified in accordance with 903.02, followed by a term describing the relative amount of gravel as follows:

20% to 35%: “with some gravel” 36% to 50%: “and gravel”

903.04Soils Having 20% or More Retained on No. 10 (2.00 mm) Sieve and 20

Less Than 20% Passing No. 200 (75 μm) Sieve These soils shall be classified as follows:

Classification Gravel, % Sand, % Silt, % Clay, % Gravel 85 – 100 0 – 15 0 – 15 0 – 15 Sandy Gravel 40 – 85 15 – 40 0 – 20 0 – 20 Gravelly Sand 20 – 40 40 – 80 0 – 20 0 – 20 Sand and Gravel 20 – 50 20 – 50 0 – 20 0 - 20

If the gradation of a given sample is not in exact accordance with the requirements for a given classification, it shall be placed in the classification to which it comes the closest.

903.05Organic Soils

The following classification system shall be used for organic soils in accordance 30 with AASHTO T 21 and AASHTO T 267.

Classification Organic Content, % With Organic Matter* 4 - 15 Organic Soil (A-8)* 16 - 30 Peat (A-8) More than 30 * Soils classified in accordance with 903.02 shall also include this classification. 903.03

903.06Marly Soils

The following classification system shall be used for marly soils with calcium and magnesium carbonate content in accordance with ITM 507.

Classification Percentage With Trace Marl* 1 - 9 With Little Marl* 10 - 17 With Some Marl* 18 - 25 Marly Soil (A-8) 26 - 40 Marl (A-8) More than 40 * Soils classified in accordance with 903.02 shall also include this classification.