Effect of adhesion additive and nature of filler on interfacial interaction and fatigue parameters of asphalt mastic

Introduction. The effect of adhesion additive and nature of filler on fatigue life and interfacial interaction in mastic is analyzed in this paper. Materials and methods of research. Frequency sweep from 0.1 to 100 rad/s at strain 0.05% at temperatures from 30 to –10°С with a step 10°С and cyclic tests (LAS test) at temperatures from 16 to 1°С with a step 3°С for bitumen grade BND 100/130 and mastics based on it, containing fillers of different nature, were performed on the dynamic shear rheometer. Mastics were prepared by mixing bitumen (3 min; 160°С and 600 rpm) and filler (filler volume fraction – 0.275). Adhesion additive in an amount of 0.7%, was introduced into bitumen before the filler to investigate the effect of AD on the properties of bitumen and AB. The damage characteristic curve under cyclic loads was calculated using two models of VECD theory (Viscoelastic Continuum Damage Modeling System): dissipated strain energy and pseudo-strain energy. Results and Discussion. The influence of nature and properties of filler, adhesive additive, temperature and frequency of tests on the parameter of interfacial interaction K-B-G* and thickness of adsorbed layer has been investigated. The intensity of damage in the specimen under cyclic loads and the behavior of fatigue parameters as a function of test temperature at two variants of determining the parameter α have been analyzed. Conclusion. It is shown that an increase in the interfacial layer thickness in asphalt mastic leads to an increase in their resistance to damage accumulation (Damage Intensity) during fatigue testing (LAS), and lowers the rate of pseudo-deformation energy growth.