Troxler 3430-M, Manual Of Operation And Instruction

Page: 45 / 142

Model 3430 3-17
Figure 3-6 illustrates the terms void ratio and % air voids . The void
ratio is the ratio of the volume occupied by air and water in the soil
to the volume occupied by solid particles. The term % air voids
refers to the volume of air voids only as a percentage of the total
volume.
The following formulas are used to calculate the % air voids and
void ratio values.
% AIR VOIDS = 100 (1 – (Vs/Vt) – (Vw/Vt))
where:
Vs = Volume of Soil
Vt = Total Volume
Vw = Volume of Water
or,
% AIR VOIDS = 100 (1 – (DD / SG(Dw)) – (M / (Dw)))
where:
Dw = Density of Water
SG = Specific Gravity of Soil Particles
DD = Dry Density
M = Moisture
VOID RATIO = Volume of Voids / Volume of Soil
= ( SG(Dw) – DD ) / DD
Figure 3-6. Voids Illustration
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