Analysis of compressive dynamic behaviors of plain concrete and lightweight aggregate concrete

In this paper, 8 loading strain rates were configured to carry out experimental research on the compressive dynamic behaviors of plain concrete (PC) and lightweight aggregate concrete (LWAC) by utilizing a hydraulic servo machine. The compressive failure modes and stress-strain curves of PC and LWAC under various loading states were generated from the experiments. The peak stress and peak strain values extracted from the stress-strain curves, as well as the elastic modulus, were comparatively analyzed between the two types of concrete. The experimental findings indicate that the failure mode of PC under the static strain rate mainly manifest as the damage to bonding materials, while the failure under dynamic strain rates involves part of coarse aggregates. For LWAC, the failure modes under both static and dynamic loading mainly manifest as the damage to shale ceramisite. As the strain rate increases, the peak stress and elastic modulus of both PC and LWAC increase significantly. Compared with PC, the strain rate effect on LWAC is more obvious. The peak strain of both PC and LWAC varies insignificantly across different strain rates, even though the changing trend shows a discrete pattern. In addition, on the basis of the experimental results, the relationship equations between the strain rate and the related mechanical parameters were established for both PC and LWAC. It is found that the values of peak stress and elastic modulus and the logarithmic value of the corresponding strain rate after non-dimensional treatment fit a linear relationship. The findings provide theoretical insights into the research and engineering application of LWAC.