Emulsified Asphalt Residue Recovery and Characterization
Combined Use of Moisture Analyzer Balance and Dynamic Shear Rheometer
By: Arash Motamed, Delmar Salomon, Nazmus Sakib, and Amit Bhasin
A new procedure has been developed for residue recovery of emulsified asphalt. The procedure uses a moisture analyzer balance (MAB). The MAB recovery method is quick and simple compared with traditional recovery procedures such as distillation or oven evaporation. Although the MAB procedure has become an ASTM procedure, there have been a limited number of studies on the rheological properties of the emulsion residues recovered by MAB. This research used a dynamic shear rheometer (DSR) to investigate the rheological properties of MAB specimens. The MAB method was used for several types of emulsions, including cationic and anionic emulsions with several modifications. The MAB method developed in this study addresses the issue of breakdown of polymers during recovery of modified emulsions at high temperatures. The study evaluated the effect of recovery temperature on the recovery time and rheological properties of emulsion residues and proposed a new recoverycharacterization procedure. The results show that a preliminary performance grade classification of the emulsified asphalt can be made with the combined MAB-DSR procedure. Furthermore, the study quantified the effect of aging that might occur during the recovery and emulsification process on the rheological properties of the emulsion residues. The combined MAB-DSR procedure is proposed to be a cost-effective alternative method to evaluate the performance of emulsified asphalts.