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 Nf50 and NDER. 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 Nf50

the fatigue life meaning of NDER was clearer

the numerical value was easier to determine

and the obtained fatigue life loading times were smaller. The use of NDER in asphalt pavement structure design and material selection is safer

so it is recommended to adopt NDER for the analysis of the fatigue life of mortar.