Experimental study and numerical simulation of the dynamic mechanical properties of ceramsite concrete containing different types of coarse aggregates

Dynamic compression tests were conducted on ceramsite concrete with a volume fraction of 40 % using the Split Hopkinson Pressure Bar (SHPB) apparatus. Additionally, numerical simulations of ceramsite concrete were performed using the explicit dynamic finite element software LS-DYNA. The experimental results demonstrated that the dynamic compressive strength of ceramsite concrete increases with the internal strength of the ceramsite aggregates. Furthermore, ceramsite concrete incorporating crushed stone shale ceramsite (CSSC) exhibited higher dynamic compressive strength compared to concrete made with spherical ceramsite aggregates. The dynamic increase factor (DIF) and energy absorption of ceramsite concrete showed a clear correlation with the strain rate. Specifically, at a certain strain rate, the maximum energy absorption rate of ceramsite concrete exceeded 45 %. A novel aggregate placement algorithm was developed to minimize overlap between aggregates, optimize the shape and size of aggregates, and consider the effects of internal pores on the macroscopic mechanical properties of the concrete. The finite element calculation results show a high degree of fit with the experimental results, with R² values exceeding 95 %. This methodology is applicable to various types of coarse aggregate concrete, including ceramsite concrete, recycled aggregate concrete, and fiber-reinforced concrete. The engineering application of ceramsite concrete has certain guiding significance.