Humboldt H-3750.5F Relative Density Apparatus - Manual (Page 6)

Calculations
a) Minimum Density. Calculate minimum density in pounds per cubic foot,
as follows:
b) Maximum Density. Calculate maximum density, in pounds per cubic foot as
follows:
Where:
Ws = weight of dry soil, pounds
Vc = calibrated volume of mold, cubic feet
Vf
= volume of soil, cubic feet = Vc – (Ri – Rf ) / 12 x cu. ft.
Rf = final dial gage reading on the surcharge base plate after
completion of the vibration period, inches
Ri = initial dial gage reading, inches
A = cross-sectional area of mold, square feet.
c) Density of Soil in Place. Determine the density of the soil in place, Yd,
in a compacted fill or a natural deposit in accordance with either the
Method of Test for Density of Soil in Place by the Sand-Cone Method
ASTM Designation: D1556 or the Method of Test for Density of Soil in
Place by the Rubber-Balloon Method ASTM Designation: D2167.
d) Relative Density. Calculate relative density, Dd, expressed as a percentage
as follows:
Ws
Vc
g
dmin =
Ws
Vf
g
dmax =
g
dmax (
g
-
g
dmin)
g
(
g
dmax
-
g
dmin)
x 100 Dd =