Creep model of cement and asphalt (CA) mortar based on micro-meso structure

CA mortar, as a filling layer, has been widely used in slab ballastless track. Since the creep deformation directly determines the track regularity and the train ride comfort, we investigated the effect of various stress levels on CA mortar creep. Results showed that the creep strain of CA mortar increased by 10 times when the stress level increased from 10%σ_p to 40%σ_p. Furthermore, it was first discovered that creep of CA mortar was attributed to the organic–inorganic interface slip and the propagation of microcracks. This work proposed a new CA mortar creep model based on the micro-meso structure characteristics, and its accuracy of prediction was much higher than previous models, R² > 0.93.