This research mainly investigates the dynamic strength improvement mechanism of concrete materials based on two aspects: the time lapse of strain and the crack development modes. Based on the contrastive experiments on axial compression and flexural-tensile tests, the load-deflection curves under quasi-static load and dynamic load were obtained. Consequently, the stress-strain curves of concrete materials were available. Therefore, the fracture energy of the specimen was calculated through numerical integration of the load-deflection curves. The strain response under dynamic load is significantly less than that under quasi-static load at the same stress level. The time lapse of strain exists and is more significant as the stress level increases. The analysis of micropattern morphology on crack development under dynamic load shows that there is not enough time for microcracks to independently select the next weakest part for further propagation. Therefore, some cracks go through the aggregate, and more energy is required for the crack development, thus leading to an improvement of dynamic failure strength.
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