ASTM D7402-09 (R2017) PDF Download

The ASTM D7402-09 (R2017) standard provides a method to identify cationic emulsified asphalts. Cationic emulsified asphalts are identified by their migration to a negatively charged electrode (cathode) using direct current. This migration is possible because aggregates and sands used with emulsified asphalts are often predominantly either negatively or positively charged. The selection of compatible emulsified asphalts with the available aggregate or sand helps in identifying a cationic type of emulsified asphalt as defined by Specification D2397. In addition to positively charged particles, emulsified asphalts that do not show a positive charge can be classified as cationic slow-setting if they coat a specific type of negatively charged silica sand.