In order to reproduce the dynamic behaviors of RC structures under intensive loadings, e.g., impact and blast, more realistically and accurately, the dynamic interactions between the embedded rebar and concrete matrix are studied numerically. Firstly, the validations of the concrete model and corresponding parameters are verified by comparing with the available empirical formulae, related specification and tests results. Secondly, based on the calibrated concrete model, the applicability of seven interaction methods in program LS-DYNA and relevant parameters are verified and determined by simulating the pull-out and three-point flexural tests. Finally, concerning four typical intensive loading scenarios, i.e., low- and high-velocity impacts, short- and long-duration blast loadings, the simulated results such as the deflection, instantaneous crack, damage evolution and distribution derived by adopting different approaches are compared and evaluated. It demonstrates that, (i) concerning above-mentioned scenarios, the dynamic bond-slip behavior has the most significant influence on the dynamic response of the RC member under high-velocity perforation scenario, and more desirable results can be obtained without considering the bond-slip behavior under the deformable projectile high-velocity impact and long-duration explosion; (ii) for the considered scenarios, the CBISF method considering bond-slip behavior is recommended for RC member exhibiting bending failure mode under low-velocity impact, hard missile high-velocity impact, and short-duration explosion; the perfect-bond CBISP and SN approaches are suggested for the deformable missile impact and long-duration explosion conditions, respectively. The present study can provide helpful references in the numerically evaluation and design of impact and blast resistant structures.