Rheological properties of high-asphalt-content emulsified asphalt

High-asphalt-content emulsified asphalts (HIACEs) have a broad application potential in the field of asphalt mixtures due to their ultrahigh asphalt content (≥74%) and adjustable rheological properties. The latter is an important property of HIACEs that has a substantial effect on their preparation, storage, transportation, and mixing. Therefore, in this study, the rheological properties were investigated by steady-state shear tests and oscillation tests. The results show that the rheological properties of HIACEs are clearly temperature sensitive, showing a “gel-like” structure with increasing temperature, and when the temperature is higher than the temperature corresponding to the gel-like point, HIACEs behave as a pseudoplastic fluid with a yield stress. The results of amplitude scanning showed that the high HIACEs had a broad linear viscoelastic interval. Under a small amplitude (linear region) oscillation, the HIACEs had a gel-like structure within a specific angular frequency range, and the elastic behavior was more prominent than the viscous behavior. With a continuous increase in the angular frequency, the gel-like structure was destroyed. The storage modulus calculated with the use of the modified Mougel model was in good agreement with the experimental values. Also, the rheological properties of HIACEs depended on the asphalt content and droplet size, which provides theoretical guidance for the practical application of HIACEs in engineering. [Display omitted] •HIACEs has a very high bitumen content compared to conventional emulsified bitumen.•Rheological properties can affect the production, transportation and use of HIACEs.•Rheological properties of HIACEs were obviously temperature sensitive.•Rheological properties of HIACEs depend on asphalt content and droplet size.