Análise da susceptibilidade térmica de ligantes asfálticos através da energia de ativação de fluxo

Abstract

The flow activation energy (Ef) is a parameter which can be related to the thermal susceptibility of pure and modified as-phalt binders, providing useful information about their performance in service. This parameter can be obtained using either visco-simetry or rheometry. In this work, experiments for flow activation energy calculation were performed in a rotational viscometer as well as in a Dynamic Shear Rheometer (DSR). Equations used in correlations with each technique are described here. The asphalt binders that showed lower flow activation energy values are considered less susceptible to temperature variation in the temperature ranges studied. The temperature susceptibility of asphalt binders showed that EVA modified asphalt binders have lower degradation than those containing SBS polymer. It was also observed that the oxidative ageing affected the sensitivity of asphalt binders to tem-perature. Furthermore, after the oxidative ageing, the thermal susceptibility of modified asphalt binders was different, showing that polymers and additives affect in the ageing process. The additives (lime and cashew nut shell liquid) also contributed to the reduction of the thermal susceptibility of asphalt binders.