Performance of emulsion residue obtained from oven evaporation and MAB

The present study was undertaken to compare two recovery methods: oven evaporation with high temperature (OHT) as per ASTM D6934 and Moisture Analyzer Balance (MAB) as per ASTM D7404. One type of emulsion, Cationic Rapid Setting (CRS-1), commonly used in India was selected for this study. The rutting performance of emulsion residues was estimated using multi-stress creep recovery test in accordance with ASTM D7405. In addition, shear modulus (G*) and phase angle (δ), and time-temperature sweep tests were conducted for each types of residues. The results of G* and δ showed that MAB resulted in a stiffer (aged) binder compared to OHT method, due to high oxidation of emulsion in MAB. The non-recoverable compliance (J_nr) of OHT and MAB methods estimated at 3.2 kPa was found to be 6.1 kPa⁻¹ and 1.23 kPa⁻¹, respectively, indicating that residue obtained from MAB is stiffer. Furthermore, time and temperature sweep test indicated that G* of MAB residue was higher compared to OHT at low frequency and high temperature. The OHT procedure yields sufficient amount of residue and shows high repeatability in determination of residue content compared to MAB method. Therefore, it can be concluded that for Indian conditions, OHT may be a better choice than MAB. However, MAB can be a good tool for quality control of emulsions in field.