Estudo do comportamento do asfalto modificado com óleo de girassol visando à obtenção de misturas mornas.

Abstract

In the asphalt pavement sector, the emission of greenhouse gases to atmosphere is mainly due to high temperatures of mixing and compaction. The Warm Mix Asphalt (WMA) technology is an alternative process of manufacturing the asphalt mixtures. This technology provides reduction of the high temperatures of mixing and compaction and provide sustainable benefits in short, medium and long term to social, economic and environmental advantages. This research aims to study the physical and mechanical properties of asphalt mixtures with modified binder by the addition of sunflower oil. Sunflower oil, additive used in this research, was adopted because it is among the four most consumed oleaginous plants worldwide. Sunflower oil accounting for the equivalent of 8.74% of the total consumption of vegetable oils in food and industrial uses. The sunflower oil was added to the asphaltic binder in the contents of 1, 2 and 3%. In order to evaluate the physical properties of the asphalt binder with and without the additive, the physical tests of penetration, softening point and the Fourier Transformed Infra Red (FTIR) test were performed before and after the Rolling Thin-Film Oven (RTFO) in addition to the rheological test of rotational viscosity. For the mechanical characterization of asphalt mixtures dosed by SUperior PERforming Asphalt PAVEments (SUPERPAVE), the following tests were performed: Flow Number, Modified Lottman, Resilience Modulus, Tensile Strength and Fatigue Life. The results indicated technical feasibility of sunflower oil incorporation to the asphalt binder. Sunflower oil provided advantages as reducing the mixing and compacting temperatures up to 6ºC. However, this reduction does not allow classify modified binder as a typical WMA. However, mixtures produced with modified binder provided a greater increase in lubricity and resistance to moisture damage, contributing to tackiness and cohesion of the asphalt mixture and still provided an increase in fatigue strength. The specimens molded with the addition of 2% of the additive had satisfactory mechanical and volumetric properties in relation to the criteria recommended by the adopted standards.