Study of the Dynamic Mechanical Properties of Recycled Concrete Containing Ferronickel Slag Subjected to Impact

In order to study the dynamic mechanical properties of recycled concrete with ferronickel slag, dynamic experiments on cylindrical specimens (φ 73 mm × 36.5 mm) were performed using a split Hopkinson pressure bar (SHPB) system. The effects of loading rate and recycled aggregate replacement rate on the compressive strength, toughness index, peak strain, and failure pattern of the concrete were investigated, and four different loading rates and aggregate replacement rates were selected. In addition, cohesive elements were embedded between C3D8R elements in the numerical model using Python language to simulate the failure process of the recycled concrete, and the reliability of the simulation was validated by the obtained experimental results. It was found that the peak strain of the recycled concrete was significantly higher than that of the ordinary concrete; however, its peak stress was lower than that of the ordinary concrete. In comparison to the recycled concretes containing 70% and 100% recycled coarse aggregates (RCAs), the toughness index amplification of the recycled concrete containing 30% RCAs was the most obvious. The failure pattern and mechanical properties of the numerical model were consistent with those of the test specimens, thus validating the reliability of the numerical simulation.