INVESTIGATION OF DYNAMIC COMPRESSION PROPERTIES OF REACTIVE POWDER CONCRETE AFTER EXPOSURE IN HIGH TEMPERATURE

Uniaxial-compression split Hopkinson pressure bar experiments were performed for reactive powder concrete samples. Both the untreated specimens and after-exposure concretes in high temperature (400℃, 600℃ and 800℃) were tested in order to investigate the influences of hybrid fibers on dynamic mechanisms for RPC concrete after exposure in high temperature. The results show that: without burnt, a negative-mixed effect occurs on dynamic compression strength and ductile for hybrid fibers RPC material, but less evidence decreasing rate of ductility than strength. After exposure in high temperature, a positive-mixed effect occurs on dynamic compression strength and ductility. The material shows a better impact resistant and integrity than steel fiber reinforced by RPC. And hybrid RPC behaves a plastic strengthen effect character. The sample with steel fiber of 2.0% volume rate and PVA fiber of 0.1% volume rate shows a optimal dynamic mechanical property.