High-speed hydrodynamic wear of steel-fibre reinforced hydraulic concrete

The paper reports about an investigation of the erosion resistance of two types of hydraulic concrete, namely a plain hydraulic concrete (PC) and a steel-fibre reinforced hydraulic concrete (FRC). The flow erosion was simulated by high-speed water jets with velocities up to 234 m/s and impact angles of 15° and 90°, respectively. A general relationship could be found between relative erosion rate (g/g) and process parameters: ER∝vFnf(θ), with n between 1.1 and 1.25. However, it was shown that the type of pump used for the experiments was critical to these results. The reason was that water flow velocity and water mass flow rate could not be varied independently. If the absolute erosion rate (g/s)—characterised by a constant water mass flow rate—was considered, a modified relationship ĖR∝vFn+qf(θ) was derived, where q considered water volume effects. Values for q were about unity. In general, erosion rate decreased if the concrete was reinforced. However, the influence of the fibre reinforcement was more pronounced for the lower impact angle. This is explained by the formation of a ‘shadow zone’ behind the fibres in case of shallow impact angle.