Asphalt Emulsion Residue Characterization

The need for an appropriate residue recovery procedure for asphalt emulsion has been recognized in both Europe and the US. The forced airflow drying method, which dries the emulsion at ambient temperature, provides a sufficient amount of residue samples within 3-5 h for the Superpave binder characterization [22]. An example of estimating the mtting resistance temperature, (temperature at G /sin(5) = 1 kPa) of microsurfacing emulsion residue is shown in Fig. 12-16. A typ- 

As seen in Fig. 12-16, the unmodified asphalt emulsion was made with a PG64 asphalt and the rutting resistance temperature increased slightly from 66 °C to 68 °C after one month. The sample with Portland cement shows a gradual increase in to 71 °C within three weeks. This increase in is mostly due to stiffening of the asphalt as the phase angle of the residue increases from 82° to 88° at T. The value of showed a rapid increase to 76 °C within the first 3 days of curing when 3 % of the 

To evaluate potential benefits on performance during its lifetime, an accelerated curing test was also designed. Here, the emulsion was dried one day under the forced airflow, and transferred into an oven at 60 °C, and so simulating pavement temperature during the daytime. 

Two different latex polymer levels of 3 and 5 % were studied. Three PG grades improvement (from PG64 of the unmodified asphalt) with 3 % latex polymer takes only 10 days of curing, as seen in Fig. 12-17, demonstrating the rut filling capability of the microsurfacing system. 

The European Standard for emulsions of pure and polymer modified bitumen including a residue recovery procedure and characterization of the recovered residue is currently under preparation. 

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