Dynamic compression behavior of ultra-high performance cement based composites

In order to investigate the dynamic compression behavior of Ultra-high performance cement based composites (UHPCC) used in defense works, UHPCC with 200 MPa compressive strength is prepared by replacing a large quantity of cement by industrial waste residues such as silica fume, fly ash and slag; and substituting ground fine quartz sand (≤600 um in diameter) with natural sand (2.5 mm in diameter). Split Hopkinson pressure bar (SHPB) is performed on UHPCC with different fiber volume fraction to investigate the dynamic compression behavior. Results show that impact resistance of UHPCC is improved with an increase of fiber volume fraction. The dynamic compressive strength of UHPCC is also increased with an increase of strain rate. In addition, the finite element method (LS-DYNA) is employed to simulate the whole impact process of UHPCC. Numerical simulations demonstrate that the Johnson_Holmquist_Concrete material constitutive model can be used for the dynamic compression of concrete. The numerical values are in good agreement with experimental results.