Rheological study of asphalt binder modified by cotton and copaiba oils: e315

Copaiba and cotton oils have large-scale origins in the northern and northeastern regions of Brazil, respectively. Thus, this study evaluated the effects of incorporating these oils at 4 and 5% contents in Petroleum Asphalt Cement with 50/70 penetration. Binders were analyzed by physical and rheological tests: penetration, softening point, rotational viscosity, and performance grade; these tests were performed before and after the short-term aging procedure and multiple stress creep and recovery. The results showed that the addition of the oils made it possible to reduce the production temperatures of the mixtures and reduced the viscosity. Asphalt binders modified with cottonseed oil were susceptible to aging with retained penetration values below the limit established in the standard. In general, bio-oils partially replacing the asphalt binder resulted in a loss of strength in permanent deformation, but it also provided a decrease in the mixing temperature, which minimizes the consumption energy in the process.