Quasi-static and dynamic compressive mechanical properties of engineered cementitious composite incorporating ground granulated blast furnace slag

The ground granulated blast-furnace slag (GGBS) has been widely used as a supplementary cementitious material in concrete production due to its lower heat of hydration, ability to gain strength over a longer period, superior performance against chemical attacks, and lower environmental impact. Four Engineered Cementitious Composite (ECC) mixtures with 50%, 60%, 70% and 80% substitution amounts of GGBS were prepared and their dynamic compressive mechanical behavior had been investigated by using a split Hopkinson pressure bar (SHPB) system at strain rates ranging from 84.8 to 184.6 s^-1. The corresponding quasi-static compressive responses of GGBS-ECC were also studied experimentally for contrasting with their dynamic tests. The objective of using GGBS to replace fly ash in ECC was to obtain higher quasi-static compressive strength and dynamic load-carrying capacity. The dynamic compressive stress-strain curves did not show residual strength behavior as that in the quasi-static stress-strain curves. ECC incorporating GGBS exhibited strain rate dependence. The peak stress increased and the peak strain decreased with the increase of strain rates. The toughness ratio under quasi-static compression was lower than that of dynamic compression according to the proposed method in this study. The toughness ratio under dynamic compression showed a slight increase with the GGBS content increasing. The strain rate had little influence on the toughness ratio.