ASTM D1140

Determining the Amount of Material Finer than 75-μm (No. 200) Sieve in Soils by Washing

Applicability: ASTM D1140 is a standard test method used to determine the amount of material finer than the 75-μm (No. 200) sieve in soils with a maximum particle size of 75 mm (3 in.). Method A, soaking in water, is used for non-cohesive soils with little or no plasticity, while Method B, soaking in a dispersing solution, is used for soils, particularly clayey soils, whose fines are plastic and adhere to larger particles. Materials containing significant amounts of soluble substances are recommended to be tested by other methods of separation.

Purpose: The purpose of ASTM D1140 is to separate and quantify the fine fraction of a soil by wet sieving, which removes fines and breaks down soil aggregations far more efficiently than dry sieving. It is used either as a stand-alone determination of percent material finer than the No. 200 sieve or as a preparatory step before dry sieving, supporting accurate soil gradation and classification.