عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this investigation, the mechanical properties of the blends of blown bitumen110/10, heavy vacuum slops (H.V.S), bitumen 60/70 penetration grade and isotactic polypropylene (iPP) were studied for the first time. Our results showed that modulus varies non-linearly and at certain asphaltenes contents a peak appears. Considering these phenomena it is revealed that in the absence of iPP, interactions between the asphaltenes control the modulus of the blends. These interactions are dependent on the H.V.S and soft bitumen contents. The asphaltenes establish strong interactions with other asphaltene groups during dissolution in H.V.S or bitumen 60/70 (called solubility limit). At low percentges of iPP and high concentrations of asphaltenes a segregated network of asphaltenes is formed.
Formation of this network increases the modulus of blends. At higher percentages of iPP and low asphaltenes concentration an interdiffusion-coalescence network is established. This network creates transition structures and increases the blend modulus. Finally, it is found that incorporation of iPP
improves the modulus of bituminous blends.