Stress–strain relationship of steel fiber-reinforced concrete under dynamic compression

Steel Fiber Reinforced Concrete (SFRC) possesses many excellent dynamic performances such as high resistance to explosion and penetration. In the present study, three types of SRFC specimens with 0.0%, 3.0% and 6.0% (percentage by volume) of ultrashort steel fibers are fabricated and subjected to impact compression tests conducted on 74-mm-diameter split Hopkinson pressure bar (SHPB). Based on the stress–strain curves of different strain-rates, as well as the random statistical distribution hypothesis for SFRC strength, a dynamic damage constitutive model of SFRC composite under compression is proposed. The relations of main parameters with strain-rate and steel-fiber content (volume fraction) are also explored and presented in this paper. It is established that both the volume fraction of steel-fiber and strain-rate of loading exert significant influences on the SFRC strength. The new constitutive model is capable of capturing the fundamental dynamic behaviors of the SFRC composite and its theoretical results are in good agreement with experimental data.