THE SPALLING BEHAVIOUR OF REACTIVE POWDER CONCRETE

Reactive powder concrete (RPC) is prepared by replacing 60% of the cement with ultra-fine industrial waste powder. The spalling behaviour of RPC with different fiber volume fractions is studied using split Hopkinson pressure bar (SHPB). The effects of incident waves and impact times on the stress wave propagation are investigated. The program to calculate the interaction between compressive and tensile waves was developed based on one-dimensional elastic wave theory, and it was used to obtain the tensile stress distribution near the free side of the specimen. The spalling strength of the material is obtained according to the spalling position and the tensile stress distribution. The strain rate effects on spalling strength and fracture patterns are examined. Results show that (1) the amplitude of the reflective tensile wave decreases with the increase of the amplitude of the incident wave and impact times; (2) with the increase of strain rate, the spalling strength of RPC is enlarged and its fracture degree increases; (3) the depth and width of cracks on spalling diminish by the introduction of fiber reinforcement.