Analysis on fatigue performance of asphalt mortar with inorganic micro-powder filler

Abstract:

In order to explore the influence of inorganic micro-powder fillers on the fatigue performance of asphalt mortar, nine kinds of commonly used inorganic micro-powder particles in three types were used as additive mineral materials, and the morphology characteristics, filler types, and particle sizes of the micro-powder particles were investigated. The morphology characteristics of the micro-powder particles were characterized by SEM, the influence of different kinds of micro-powder fillers on the fatigue properties of asphalt mortar was studied by dynamic shear rheometer (DSR), and the fatigue life of asphalt mortar was compared and analyzed by indexes N_f50 and N_DER. Results show that under SEM, the hydrated lime particles had more surface pores and complex surface texture, and the fatigue performance of the asphalt mortar was greatly improved with the decrease in the particle size of the inorganic micro-powder filler under dynamic shear rheological test. With the same particle size, due to the special morphology characteristics and chemical compositions, the fatigue performances of hydrated lime and cement were better than that of limestone. Compared with N_f50, the fatigue life meaning of N_DER was clearer, the numerical value was easier to determine, and the obtained fatigue life loading times were smaller. The use of N_DER in asphalt pavement structure design and material selection is safer, so it is recommended to adopt N_DER for the analysis of the fatigue life of mortar.