DGSI. Durham Geo Slope Indicator

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.

vacuum pycnometer
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.

vacuum pycnometer
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

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.
Specific Gravity Submersion Tank

Designed to enable measurement of the specific gravity of compacted and uncompacted bituminous mixtures as well as other materials.

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.

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.