Multi-scale measurement of constitutive viscoelastic properties of bituminous composites considering moisture and deicing conditions

The use of salt and chemical deicers can cause significant damage to road infrastructures. This study investigates the impact of different deicers on the viscoelastic properties of mastic and asphalt mixtures, with a focus on characterizing their behavior at varying temperatures and loading frequencies. The samples were subjected to conditioning in solutions of distilled water, salt, Calcium Magnesium Acetate (CMA), and Potassium Acetate (KAc) at 60 °C for 96 h, followed by frequency sweep and dynamic modulus tests at different temperatures and loading frequencies. The results indicate that moisture conditioning with distilled water softens asphalt mixtures and mastic at low loading frequencies, while brine softens the former at low temperatures. Salt's high interaction with mixture aggregates cannot be ignored. CMA's effect on the fatigue behavior of mastic samples is highly dependent on loading frequency, while KAc increases stiffness at intermediate and high temperatures. All the deicers reduce resistance to rutting damage, with CMA having the most negative effect. Both the 2S2P1D and the generalized Maxwell model can well (R² ≥ 0.90, S_e/Sy ≤ 0.35) predict the viscoelastic properties of dry asphalt mixture. However, in the presence of distilled water and the deicers, asphalt mixture viscoelastic properties cannot be predicted according to asphalt mastic characteristics by implementing the homothety method which indicates different effects of distilled water and the deicers on various scales of bituminous composites.