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

• The range of actual strain rate of CA mortar was calculated.
• The dynamic mechanical properties of CA mortar can be studied by SHPB test.
• The microscopic mechanism of dynamic mechanical properties was analyzed.
• The specific energy absorption increases with the increase of strain rate.
• The established constitutive model agrees well with the experimental results.

In order to study dynamic mechanical properties of cement and asphalt mortar (CA mortar), the compressive stress–strain experiment of CA mortar at intermediate strain rates was carried out by split Hopkinson 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.