What is the Plastic Limit?

The plastic limit is defined as the moisture content at which a soil becomes plastic. It is the boundary between a soil’s solid and plastic states. ASTM D4318 is the standard test procedure for determining the plastic limit. Of course, a soil doesn’t go from solid to plastic all at once, but the standard test […]

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What is the Shrinkage Limit?

The shrinkage limit of a soil is the moisture content at which: the soil is considered saturated. any loss of moisture will not result in any volume changes. The shrinkage limit is much less commonly used than the other Atterberg limits, the plastic limit and liquid limit. I have never seen the shrinkage limit reported […]

How to Determine the Atterberg Limits

Based on moisture content, a soil can exist in four possible states: Solid Plastic Liquid The Atterberg limits, created by swedish chemist Albert Atterberg, are simply the moisture content, usually reported in percent, at which the soil changes state. They are defined as: Plastic Limit (solid – plastic) Liquid Limit (plastic – liquid) Some textbooks […]