Dynamic Properties of Concrete at Moderately Elevated Temperatures

Reinforced concrete is widely used to not only provide structural support but also to mitigate the effects of radiation, malevolent attacks, and dynamic accidents. Dynamic tests were performed on 102 x 203 mm (4 x 8 in.) normalweight concrete (NWC) and fiber-reinforced concrete (FRC) cylinders using a drop hammer. Dynamic splitting tension and dynamic compression tests were performed at room temperature and at 204[degrees]C (400[degrees]F). The dynamic increase factor (DIF), which is the ratio of dynamic to quasi-static strength, and the strain rate were compared to existing models. The DIF for tension and compression increased with strain rate. For compression, a DIF up to 3.2 was recorded for strain rates up to 12 [s.sup.-1]. For tension, a DIF up to 4.1 was recorded for strain rates up to 1.8 [s.sup.-1]. Heated NWC and FRC specimens had lower DIFs compared to room-temperature specimens for dynamic compression and tension. The experimental DIFs followed closely the Modified Comite Euro-International du Beton (CEB) model for tension. Keywords: compression; drop hammer; dynamic increase factor; fibers; strain rate; temperature; tension.