The impact of ageing on the bitumen stiffness modulus using the cam model

• Main Authors: Małgorzata Cholewińska, Marek Iwański, Grzegorz Mazurek
• Format: Article
• Language: English
• Published: RTU Press 2018-03-01
• Series: The Baltic Journal of Road and Bridge Engineering
• Subjects: christensen−anderson−marasteanu (cam) model; long-term ageing; short-term ageing; viscoelasticity; warm mix asphalt technology
• Online Access: https://bjrbe-journals.rtu.lv/article/view/2602
• ISSN: 1822-427X; 1822-4288

This article presents the results of the viscoelastic properties of the polymer-modified bitumen produced in Warm Mix Asphalt technology. A Fischer-Tropsch synthetic wax and a liquid surface-active agent (fatty amine) were used as bitumen viscosity-reducing modifiers. All tested parameters were determined after short-term and long-term ageing. The complex modulus G* and phase angle δ were measured with a cone-plate rheometer. All dynamic tests were performed at 60 °C within the frequency range from 0.005 Hz to 10 Hz. On the basis of the rheological index R determined using the Christensen−Anderson−Marasteanu (CAM) model, it was found that the fatty amine additive slowed down the age-hardening process in the bitumen. In contrast, the synthetic wax increased the stiffness of the bitumen at all levels tested, regardless of the type of ageing simulation process.