High temperature performance of asphalt modified with Sasobit and Deurex

Document Type

Article

Publication Date

3-10-2018

Department

Department of Civil, Environmental, and Geospatial Engineering

Abstract

Warm Mix Asphalt (WMA) is a valued and effective technology to decrease asphalt binder's viscosity in order to save energy and to reduce the release of carbon dioxide (CO2). Sasobit (an organic additive) is a widely used warm mix additive, which has been studied in several aspects by some researchers such as the increase of physical properties as well as the increase of rheological properties of asphalt binder. Deurex (natural sugar cane wax or free of paraffins), which is similar to the Sasobit, can be seen as a new warm mix additive. The study aims to assess the high temperature rheological properties and viscosity reduction of asphalt which is modified with the two additives: Sasobit and Deurex. During the study, Deurex was added into the base asphalt in same proportion as the Sasobit as 0%, 1%, 2% and 3%, so 16 different binders could be obtained. Above all, the study conducted the Rotational viscometer test (RV), which separately and together measured the two additives’ effects for the viscosity of the binders. The conventional tests results reveal that adding Deurex to the Sasobit can improve the cracking properties of binders as compared to the Sasobit at low temperature. And the viscometer test results reveal that both Sasobit and Deurex can reduce the viscosity and the Sasobit can be more effective than Deurex when the content of additive is low. Furthermore, the decrease of asphalt binders’ viscosities is more obvious at lower temperature. Then the study conducted the Dynamic shear rheometer (DSR) test including the Performance grade, frequency sweep and temperature sweep tests. G∗(complex shear modulus) and δ (phase angle) can be measured in the test, and the results reveal that the Sasobit and Deurex increase the value of G∗ and decrease the value of δ. Therefore, the rutting factor G∗/sinδ is improved. In other words, the high temperature properties of modified asphalt binders are increased, particularly the ability of resistance to deformation. The test also found that the 2%Deurex play a relatively big efficacy with Sasobit. Finally, the Fourier transform infrared spectroscopy (FTIR) test was used to analyze the modification mechanism of the modified binders. All in all, the Sasobit and Deurex modified asphalt do have a good performance in high temperature. And 2%Deurex with 2% or 3%Sasobit is recommend.

Publication Title

Construction and Building Materials

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