Dynamic mechanical properties of cement and asphalt mortar based on SHPB test

摘要

In order to study dynamic mechanical properties of cement and asphalt mortar (CA mortar), the compres-sive stress-strain experiment of CA mortar at intermediate strain rates was carried out by split Hopkin-son pressure bar (SHPB). The experimental results show that the peak strength of CA mortar increases with the increase of strain rate, and the growth rate decreases gradually. The discrete dynamic Young's modulus is 19.04-380.82 times as big as that at the quasi-static loading rate. The specific energy absorption of CA mortar increases exponentially with the increase of strain rate. Dynamic constitutive model of CA mortar was established, and agreed well with experimental results. The parameter m mainly influences the peak strength of constitutive model, the peak strength increases with the increase of m. While the parameter n mainly influences the descent velocity of stress of constitutive model after peak strength, and the bigger n is, the bigger the descent velocity is. The study results can provide theoretical reference for the structural design of ballastless slab track.