# Air Content

Written by Jerry Ratzlaff on . Posted in Geotechnical Engineering

Air content, abbreviated as A, is the ratio of volume of air to total volume of soil.

## air content formula

 $$\large{ A = \frac{V_a}{V_t} }$$ $$\large{ A = n \; \left( 1 - S \right) }$$ $$\large{ A = \frac{ e \;-\; w \; G_s }{ 1 \;+\; e} }$$

### Where:

$$\large{ A }$$ = air content

$$\large{ S }$$ = degree of saturation (expressed as %)

$$\large{ n }$$ = porosity

$$\large{ G_s }$$ = specific gravity of soil

$$\large{ V_t }$$ = total volume of soil

$$\large{ e }$$ = void ratio

$$\large{ V_a }$$ = volume of air

$$\large{ w }$$ = water content (% moisture contemt)