Análise da influência da variação de temperatura no desempenho de pavimentos asfálticos à fadiga a partir do modelo S-VECD

Abstract

Asphalt mixes show a strong correlation between its temperature and its mechanical properties. In Brazil, it is used the DNER design method, which does not consider temperature in order to evaluate the behavior of asphalt mixes under traffic loads. Therefore, in regions with high temperature variation during the year or, even, during the day, which is the case of the central region of Rio Grande do Sul, it is not taken into account the influence that these variations have in the mix mechanical parameters. Thus, it is necessary to adopt a new methodology that takes into account the thermal susceptibility of asphalt concrete layer. In order to investigate this influence, one can use tools that analyze viscoelastic properties of pavements. In the current research, the LVECD software was used with viscoelastic inputs from complex modulus test, fatigue inputs obtained from direct tension cyclic fatigue test and temperature inputs which simulate climate in Santa Maria/RS with its daily and seasonal thermal variations at various pavement depths and, thus, to obtain fatigue damage with S-VECD model. Results were compared with simulations run at different temperature conditions and transfer funtions proposed by Nascimento (2015) were applied to convert damage into percent cracked area and to compare this approach with MeDiNa’s, the new national design method. The results showed that the consideration of temperature change resulted in lower damage and cracked area values for the studied cases when compared with results considering constant temperature. Besides that, economic analysis showed that LVECD resulted in lower costs per load application than MeDiNa.