O efeito da modificação de ligante asfáltico com uma resina fenólica: cardanol-formaldeído

Abstract

The asphalt from petroleum refineries, when presents proper consistency to pavement, is denominated asphaltic binder or petroleum asphaltic cement (PAC). The petroleum asphaltic binders are materials constituted by complex mixtures of high-molecular-weight hydrocarbons. Their main components are carbon, hydrogen, but also contain other elements like oxygen, sulphur and some metals. They are obtained from the natural evaporation of deposits located on the earth surface (natural asphalt), or by distillation in industrial units specially designed for this. The asphaltic binders produced by petroleum refining resist satisfactorily in most situations to which pavements are submitted. Nevertheless, over the past years, the highways with a high volume of traffic have had to support an increasing daily average of vehicles, heavier trucks, and also increases in axle weight and in tire pressure. These roads require, thus, asphaltic coatings with better performance and more modern constructive techniques. In view of this, this research has as its goal to study the effects resulting from the modification of the petroleum asphaltic cement (PAC) by the addiction of a resin of the type phenol-formaldehyde – obtained from cardanol – to analysis of the feasibility of this additive in asphalts. Through this study, it was found that the additive enabled an increase in the module (G*) and a lowering of the phase angle (δ) that resulted in a better performance of the asphaltic binder in terms of permanent deformation if compared to the pure PAC. It was also observed a reduction of approximately 12°C in the temperature of compaction and machining of the mixture in relation to the pure binder, what makes possible the use of the resin as additive in asphaltic binders.