Speaker
Description
Abstract. Polymer-modified bitumen performs better at different tempera-tures and loading conditions than pure bitumen. Therefore, using this type of bitumen in recycled asphalt mixtures containing reclaimed asphalt (RA) material can lead to a better performance than pure bitumen. However, the presence of a very hard and aged binder in the RA, especially for high RA incorporation ratios, may increase bitumen stiffness and negatively affect the performance of the polymer-modified bitumen. Therefore, it is essential to know the effect of recovered binders on the characteristics of polymer-modified bitumen. This study investigated the characteristics of an elasto-meric polymer-modified bitumen combined with 30% recovered bitumen and a rejuvenating agent using penetration grade, softening point, viscosity, and elastic recovery tests. By analysing the master curves obtained from dynamic shear rheometer (DSR) tests in a wide range of temperatures and loading frequencies, the rheological characteristics of the same bitumen were also evaluated and compared to commercial bitumen samples (i.e., polymer-modified bitumen and pure 70/100 pen grade bitumen). The con-ventional test results showed that the recovered bitumen from RA increases the stiffness of polymer-modified bitumen even with a rejuvenator. How-ever, the DSR test results showed that it is possible to maintain the rheo-logical characteristics of polymer-modified bitumen combined with 30% recovered binder and a rejuvenator.
