Avaliação da relação entre o dano por umidade e a permeabilidade de misturas asfálticas contendo cinza volante como fíler

Abstract

Within the asphalt surface layer, the water can interfere in the binder/aggregate adhesion and in the cohesion of the binder itself, accelerating damage mechanisms such as fatigue damage. However, an adhesive and cohesive failure are the last stages of a process that begins with an infiltration of water in the structure. The coefficient of permeability (k) has been a parameter commonly used for characterizing the drainage capacity of asphalt mixtures. Thus, this work aims to evaluate the relationship between the moisture damage and the permeability in asphalt mixtures composed of different fillers: natural and fly ash. For this, it was ana-lysed asphalt mixtures with 4% of natural filler and Air Voids (AV) of 4% and 7%, besides asphalt mixtures with fly ash as a filler (also 4%) and the same AV (4 and 7%) were evaluated. In order to evaluate the moisture damage, the Lottman, as well as the Digital Image Processing (DIP) were used. The results were shown that it can exist a strong relationship (R2 = 0.98 for unconditioned samples and R2 = 0.75 for conditioned samples) between moisture damage and permeability for asphalt mixtures. The fly ash evaluated in this work did not act as a moisture damage additive, which can be explained by its chemical composition and or its used content.