The Atterberg limits, created by swedish chemist Albert Atterberg, are the moisture content, in percent, at which the soil changes state. They are defined as: Plastic Limit (solid to plastic) Liquid Limit (plastic to liquid) Some textbooks often refer to a third Atterberg limit, the “shrinkage limit” which defines the boundary between “solid” and a […]

## How to Calculate Relative Density

Relative Density is the ratio of the density of a substance to a specified reference density. Where: Dr = Relative Density (dimensionless) ρs = bulk density of soil (kg/m3 or lb/ft3) ρref = bulk density of reference (kg/m3 or lb/ft3) Often, the reference density is that of water, 62.4 lbs/ft3 or 1000 kg/m3. Alternatively, the […]

## How to Calculate Specific Gravity

Specific Gravity is the ratio of the density of a soil to the density of water. Where: SG = Specific Gravity (dimensionless) ρs = bulk density of soil (kg/m3 or lb/ft3) ρw = bulk density of water (kg/m3 or lb/ft3) = 1000 kg/m3 (62.4 lb/ft3) Specific Gravity of Various Substances Substance Specific Gravity Water 1.0 […]

## How to Calculate Bulk Density

## How to Calculate Degree of Saturation

## How to Calculate Soil Porosity

## 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 […]