Static mechanical properties and stress wave attenuation of metaconcrete subjected to impulsive loading

To mitigate shock wave propagation, a conventional engineered aggregate (EA) consisting of solid core coated with relatively soft material was designed to be tuned at targeted frequencies based on the local resonance mechanism. Previous studies demonstrated that metaconcrete consisting of conventional engineered aggregates (EAs) exhibited favourable attenuation performance of impulsive loading effects on structures. However, it was also found that the existence of the soft coating on conventional EA caused a reduction in the compressive strength of metaconcrete. In this study, a new type of EA by adding a relatively stiff shell outside the soft layer of the conventional EA was developed to overcome the issue of strength reduction whilst keeping its favourable wave attenuation properties. Quasi-static mechanical properties of metaconcrete consisting of conventional and newly developed EAs were examined through standard compression tests. The dynamic responses of the cylindrical metaconcrete specimens subjected to non-destructive and destructive impulsive loadings were also tested to investigate its wave attenuation capacity. The failure processes and the failure modes of metaconcrete made of different types of EAs under destructive tests were compared. It was found that adding a stiffer shell to the conventional EAs can improve the mechanical properties of metaconcrete while still keeping its good performance in mitigating stress wave propagation under both destructive and non-destructive loads.