Utilização do óleo de canola para redução das temperaturas de usinagem e compactação de misturas asfálticas.

Abstract

In recent years, several techniques have been developed in order to reduce mixing and compacting temperatures of conventional asphalt mixtures, which cut pollutant emissions and energy consumption. In this scenario, the warm mix asphalt (WMA) has been developed, which refers to mixtures composed of aggregates and asphalt binder modified by additives either of chemical or organic nature, or foamed asphalt, leading to drops in the production temperatures and improving the workers’ health safety during paving execution. This study has as objective to assess the physical and mechanical properties of asphalt mixtures composed of asphalt binder modified by the canola oil addition. The canola oil was used as a viscosity-modifier additive due to its low cost and great availability in the market. Samples of pure binder and binder modified with 1.0; 2.0 and 3.0% canola oil were tested. The research was divided into three stages: the first stage remarks the physical characterization of the asphalt binders before and after the Rolling Thin-Film Oven (RTFO) procedure; the second step concerns the design of the mixtures performed following the SUperior PERforming Asphalt PAVEments (SUPERPAVE) methodology, obtaining an optimal binder content of 5.1 %; at last, the mechanical characterization of the asphalt mixtures was carried out by performing the following tests: Flow Number, Modified Lottman, Resilience Modulus, Dynamic Modulus, Indirect Tensile Strength and Fatigue Life. In general, all samples with canola oil achieve mechanical results within the parameters established by the current requirement. The results show that the canola addition in the asphalt mixtures reduces the mixing and compacting temperatures up to 6 °C, yet this reduction does not allow the classification of the modified binder as a WMA. It is impossible to reduce the possibility of a classification of the modified binder in a typical MAM. It was concluded that due to the decrease in the fatigue life and the reduction of about 50% of the flow number in relation to the reference mixture it is not possible to indicate the use of the asphalt binder with canola oil. However, asphaltic mixtures with oil presented positive aspects, increasing the resistance to the deleterious action of water.