Asphalt > Specific Gravity
Measurement of the bulk specific gravity of asphalt is used primarily
for quality control evaluation of bituminous mixes. Specific gravity
is defined as the ratio of the mass of a given material to that of an
equal volume of water at the same reference temperature.
In material testing the three most common forms of specific gravity
are: specific gravity of solids, apparent specific gravity and bulk specific
gravity. Specific gravity of solids is generally applied to soil and
considers only the solid fraction as if the voids of fluid or gas were
not present. Apparent specific gravity includes in the measurement any
voids within a solid material, such as aggregate. Bulk specific gravity
includes both voids within individual particles as well as voids between
the particles, such as a compacted asphalt mix sample.
 Large
Capacity Vacuum Pycnometer
Vacuum pycnometers are used in Rice testing to determine the specific gravity
of bituminous mixes. The large capacity vacuum pycnometer has a 10 liter
(2.64 gal) capacity and will accept an asphalt sample up to 6000 g with
a maximum aggregate size of 2 in. The 10 ¾ in. diameter vessel is constructed
of lightweight polycarbonate. The transparent dome cover permits easy observation
of bubble release during testing. The A-520 set includes water inlet valve
with a ¼ in. I.D. hose, quick disconnect, vacuum hose and
an aspirator with 3/8 in. NPT fittings. |
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 2000g
Vacuum Pycnometer
The A-516 is used in Rice Testing for bituminous mixes with maximum aggregate
size of ¾ in. (19.1 mm). The 2000 g capacity vacuum pycnometer has 4.5
liter (1.2 gal) capacity. A transparent lid on the pycnometer allows
the operator to observe the bubble release from the asphalt sample during
the vacuum test. A second volumetric lid of machined aluminum, tapered
with a capillary bore, is provided so the unit can be used as a volumeter
for determing the specific gravity of compacted bituminous mixes. A-518
is a 1500 gram capacity pycnometer with a 4-in. deep chamber. It is used
for mixes with aggregate sizes up to 0.5 inch.
Both models include an aluminum volumetric canister, volumetric
lid, flat Plexiglass vacuum lid with O-ring, volumeter, release valve, fittings, a metal aspirator with 3/8 inch
IPT fittings and 6 ft of hose. Applicable Standards: ASTM D 2041
(Type E) AASHTO T 209, T 283
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 Rice
Test Vibrators
Rice Test Vibrators provide consistent shaking of vacuum pycnometers. Case
has built in 99 minute timer, vibration rate control and a 3-position switch
for manual or timed operations. |
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 Specific
Gravity Submersion Tank
Designed to enable measurement of the specific gravity of compacted and
uncompacted bituminous mixtures as well as other materials. |
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 Residual
and Closed End Pressure Manometers
The A-512 Residual Pressure Manometer is used in the Rice Test method
and is mandatory for ASTM D 2041. The sliding scale is graduated from
below zero to 130 mm by 1 mm intervals. The U-shaped tube is mounted
on a wooden stand and comes complete with mercury.
Model A-513 Closed End Pressure Manometer is an absolute pressure
gauge with a range of 1-150 mm consisting of a glass U-tube sealed
at one end, containing a measured amount of mercury and mounted
in a glass dome. The scale is graduated 0 to 75 mm in 1 mm divisions,
upward and downward from mid-scale zero. Tubulations on the base
take 1/4-in. tubing. The device is constructed to retard mercury
surge when the vacuum is released.
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Erlenmeyer Flasks as Vacuum Pycnometers
Two and four liter thick walled glass Erlenmeyer flasks are often used
as pycnometers. Flasks have side tubulations for 3/8-in vacuum tubing.
Optional neoprene stoppers with a single hole for 3/8 in. diameter glass
tubing are sized for each flask. An aspirator or vacuum pump is used
to provide the vacuum and A-512 or A-513 Pressure Manometer is used to
establish the desired vacuum. |
Overview
Marshall Stability
Specific Gravity
Asphalt Extraction
Ovens
Asphalt Ignition Ovens
Water Baths
Scales and Balances
Particle Size
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