Effect of dimensions of specimens on the impact performance of concrete

Mechanical properties of concrete are size dependent. While many reports have discussed the size effect of the test specimen on the static properties of concrete, research on the effect of cross-sectional dimensions of the concrete beams on its impact performance is still scarce. This research experimentally evaluates the relationship between the cross-sectional dimensions and orientation of the concrete beam specimens on their impact performance. Repetitive drop-weight test was used to evaluate the impact energy absorption capacity of different concrete beams. A loading protocol to evaluate the impact energy of concrete beams having different cross-sectional dimensions was proposed. The results revealed that the impact performance of concrete is size dependent. Strong proportional relationships between the moment of inertia, cross-sectional area and impact energy were found. As the moment of inertia and cross-sectional area of the test specimen increase, its impact energy exponentially increases. Furthermore, a linear proportional relationship was found between the normalized impact energy and the normalized cross-sectional area × moment of inertia. This means that the impact performance of concrete beams depends on both their cross-sectional area and orientation. The proposed loading protocol has been proven to be able to accurately evaluate the impact energy of concrete specimens with significantly varying impact performance while importantly saving time.