Abstract:
The economic development, resulting in increased traffic and, thus, higher traffic loads, often cause serious asphalt pavement problems, such as permanent deformation, fatigue cracking, and reduced lifetime. Polymers are seen as viable additives into asphalt to minimize these problems. However, its incorporation tends to reduce the workability of the material due to the increase in the viscosity of the blend. Besides polymers, oils have also been considered to improve asphalt performance. This study aimed to evaluate the effect of the addition of soybean oil on the physical, rheological, and thermal properties of high-density polyethylene (HDPE) modified asphalt binder.
The percentage ed was 5 wt.% and soybean oil was varied from 0 to 7 wt.% into asphalt. The performance of asphalt binders containing HDPE and soybean oil was evaluated using conventional tests (penetration, softening point and ductility) and rheological performance tests (dynamic viscosity and short-term ageing (RTFO) and thermogravimetric analysis (TGA). The tests results showed that the addition of 5 wt.% HDPE reduced the penetration and increased the softening point and viscosity. The oil reduced steadily the viscosity and improved the workability and the thermal susceptibility of the modified asphalt. TGA curves revealed an increase in thermal stability for samples with up to 3 wt.% of oil. The oil reduced about 92 % mass gain of the samples after ageing. Hence, soybean vegetable oil was considered a good modifier agent for improvement of polymer modified asphalt workability at service conditions
