Analysis of the concrete behaviour in tension at high strain-rate by a modified Hopkinson bar in support of impact resistant structural design

The strain-rate sensitivity of concrete in tension has been investigated employing Hopkinson bar techniques. The devices used have allowed the successful testing of large specimens with real size aggregates. Full stress-strain curves, including the softening branch, have been obtained for several strain rates. The use of bar bundles for holding the specimens has further provided insight on the fracturing mechanism inside the specimen, revealing amply the crack multi-activation process under dynamic loading. Such data are considered essential in the impact and blast resistant design of concrete structures.