Shock-absorbing capability of lightweight concrete utilizing volcanic pumice aggregate

In this study, shock-absorbing capability of lightweight concrete utilizing volcanic pumice as coarse aggregate was experimentally investigated, for application to buffer material. In the impact test, a falling weight impact tester was employed, with placing buffer layer concrete on base layer concrete. Type of coarse aggregate, water-to-cement ratio, thickness of buffer layer and impact velocity were considered as experimental factors, and the experiments were designed with the Taguchi method. Sizes of specimens and levels of experimental factors were selected based on actual phenomena observed in sediment disasters. As a result, the lightweight concrete is proved to have a superior shock-absorbing capability than control concrete using crushed limestone as coarse aggregate. Statistical analysis results indicated that the lightweight concrete is by averages of 28% and 41% more effective in reducing the maximum impact load than the control concrete, under the impact velocities of 1.5 m/s and 4.5 m/s, respectively.