Composite Approach to High Strain-Rate Stress-Strain Curve of Reactive Powder Concrete

In this study, we investigate the stress-strain curves of reactive powder concrete (RPC) at high strain rates by using SHPB test, the Burgers’ mechanics model and secant-moduli method. The RPC composites are examined at the age of 10 days containing RPC mortar as the matrix, and three volume concentrations, 1%, 2% and 3%, of steel fiber as the inclusion respectively. Strain rates including 1×10 1 ×10/sec by means of SHPB are applied to RPC. From the reproduced stress-strain curves of RPC matrix at a given strain rate by Burgers’ model, a secant-moduli method is adopted to predict stress-strain curves of RPC composites. Results indicate that dynamic four-parameter model with parameters, ) ( k 1 ε& , ) ( k2 ε& , ) ( η1 ε& , and ) ( η2 ε& , can well simulate the stress-stain curves of RPC without steel fibers. The proposed composite method is capable of predicting the stress-strain relations of RPC composites in high strain-rate regimes, especial for strain rates approaching to 1000/sec.