Static and dynamic mechanical properties of high early strength alkali activated slag concrete

In this study, high early strength alkali activated slag concrete (AASC) was prepared successfully. The compressive and flexural strength with 3 h of water curing reached 39.2 MPa and 3.26 MPa, respectively. A 100 mm diameter split Hopkinson pressure bar (SHPB) system improved by the pulse shaper technique was used to conduct the impact compression test on AASC. The stress–strain curves under different average strain rates were drawn. Based on this, the dynamical compressive mechanical properties of AASC were investigated. The results show that AASC at 3 h of curing possesses excellent dynamic performances including high dynamic compressive strength, good impact toughness and strong ability of deformation. Like ordinary Portland cement concrete (OPCC), AASC belongs to rate-sensitive materials. The dynamic increase factor (DIF), max strain, peak toughness and specific energy absorption (SEA) increase with average strain rate in AASC. Some differences between OPCC and AASC are also observed. As compared to OPCC, AASC has lower DIF, higher deformability and better impact toughness. These differences may be due to the less compact microstructure caused by insufficient curing.