Tests for asphalt emulsions are devised to measure the emulsion properties, since these are the properties needed for handling and breaking, and the residual asphalt properties, since these will be the properties of the asphalt after break.

Viscosity.

The viscosity of the emulsion is measured to determine uniformity and conformance to application needs. In the test a sample is brought to the test temperature (77°F or 122°F) and poured into the Saybolt viscometer. The flow of emulsion through an orifice into a flask of known volume is timed. When the flask is filled, the number of seconds is recorded and checked against specifications.

Sieve Test.

This test measures the amount of foreign material or unemulsified asphalt in the emulsion. These materials can clog nozzles in a distributor truck and result in non-uniform application. A sample of emulsion is poured through a screen with specific opening sizes. Material retained on the screen is measured and expressed as a percent of the original emulsion.

Demulsibility.

This test measures the stability of the emulsion (resistance to break) and distinguishes between RS, MS, and SS types. In the test a known amount of chemical (Calcium Chloride for anionic emulsions and Sodium Dioctyl Sulfosuccinate for cationic emulsions) is added to a specific amount of emulsion. The amount of emulsion that breaks is measured and reported as a percent of the amount of asphalt in the emulsion.

Distillation.

In this test we measure the amount of asphalt in the emulsion and secure a sample of the residual asphalt for further testing. A known amount of emulsion is heated in a still to either 350°F or 500°F, depending on the requirements of each material. This heating drives off the water. The remaining asphalt is weighed to determine the asphalt content of the emulsion. The residual asphalt is poured into molds (penetration, ductility, or float) for further testing.

Penetration.

The penetration of the residual asphalt is measured to determine stiffness. The procedure is identical to that of .

Ductility.

The ductility of the residual asphalt is measured to determine cohesiveness. Polymer-modified emulsions will get a low-temperature ductility measurement. The test procedure is identical to that for asphalt cement.

Float Test.

The float test is a measure of the stiffness of the residual asphalt, but it is specifically designed to show the gel structure in a high float emulsion residue. A thimble-shaped mold with no top or bottom is filled with molten asphalt and allowed to cool. This mold is attached to a funnel-shaped float with the filled thimble plugging the hole in the funnel. This whole setup is floated in a 140°F water bath until the asphalt flows from the thimble and the float apparatus sinks. The number of seconds until sinking is reported.