Petroleum asphalt cement (PAC) is a very viscous material, semi-solid or solid at room temperature, presents thermoplastic behavior and is used in paving service. For PAC to be used, an asphalt emulsion must be produced, composed of PAC itself and an emulsifier, which provides a load to the Petroleum Asphalt Cement, giving rise to anionic, cationic, or bi-ionic emulsions.

PAC and the cement test

When we have an asphalt emulsion, we need to perform a series of physical-chemical characterization analysis of the emulsion itself and tests on the residue, which is nothing more than the PAC modified with the emulsifier. These tests are present in ASTM D244 and are called “cement test”, and are divided into emulsion composition tests, consistency, stability, residue analysis, setting time, and more specific tests.

The emulsion composition tests are the first to be performed. These tests include water content in the emulsion, residue after evaporation – expedite and oven – these two tests together give us the result of the amount of solids in an emulsion. Also, particle charge tests are performed, to find out if it is anionic, cationic, or bi-io.

Physical-chemical tests are done, and now?

Once the results of the physical-chemical characterization of the emulsion are in, we move on to the consistency tests, which are carried out through the viscosity consistency tests that are performed through Saybolt Furol viscosity and stability tests where demulsibility tests are performed, which is the ability that oils have to separate from water; cement mixing, which is the ability of the asphalt emulsion to be mixed with certain types of aggregates without rupture of the emulsified asphalt; sieve test to identify the to identify the amount of PAC not dispersed in the emulsion; coating test; emulsion miscibility test of the emulsion in water, freeze test, water resistance test; Emulsion storage stability test.

Next, tests are performed on the residue, i.e., on the undispersed PAC in water. In this phase are performed characterization tests of rupture time, test of coatings by application among others, are more specific tests.

It is extremely important to perform all the tests before defining the application of the asphalt emulsion, whether for priming, waterproofing, tack coat, slurry seal, among others. Feel free to contact us if you have any doubt.