Requirements of specimen dimension considering maximum coarse aggregate size for concrete split Hopkinson pressure bar tests

•SHPB tests were performed for mortar and concrete to examine the aggregate effect.•Aggregate size relative to specimen size affected the dispersion of the apparent DIF.•Pure rate DIFs were different between specimens with small and large aggregates.•Pure rate DIFs obtained from SHPB tests were verified through numerical analysis.•Criteria for specimen preparation for SHPB test are recommended. Dynamic increase factors (DIF) of concrete compressive strength have been proposed through experiments on specimens including small aggregates without considering the effect of the coarse aggregate size, which was due to the limitations in the size of specimens and test apparatus. Therefore, this study conducted an experimental investigation of the effect of the maximum coarse aggregate size (Gmax) on the DIF of normal-strength concrete. Split Hopkinson pressure bar (SHPB) tests were performed for mortar and concrete specimens with various sizes of Gmax, and the apparent and pure rate DIFs were obtained. Moreover, the pure rate DIF of each Gmax was verified through numerical analysis of the SHPB tests. The test and analysis results indicated that Gmax affected the dispersion of the apparent DIF and the values of the pure rate DIF. Based on these results, a guideline for the fabrication of specimens considering Gmax for concrete SHPB tests was suggested.