Mitigation of the blast load on RC column by hanging granite slabs

Reinforced concrete (RC) column, which is the critical axial load carrying structural component, is vulnerable to blast loads, especially to close-in blast loads. The blast damage of the RC column might lead to the progressive collapse of the whole building structure. Therefore, it is necessary to ensure that the RC column could survive under design blast loads once the building structure is at the risk of terrorist or accidental explosions. One of the solutions is that the RC column is designed to be strong enough to resist the blast loads, which is very expensive. While the other method is to protect the RC column against blast loads with energy absorb materials. The granite slab, which is often used as the decoration hanging outside the structural components, is utilized to mitigate the blast loads applied on the RC column. In this study, firstly the concept of hanging granite slab for mitigating blast load on RC columns is proposed. Furthermore, the finite element (FE) model for simulation of the blast wave interaction with the dry-hanging granite slab is established to reveal the protection mechanism of RC column hanging with granite slab based on the platform LS-DYNA. The accuracy of FE model is validated by comparing the numerical results and the test results from blast field test. The influences of slab thickness T and hanging distance D on blast mitigation are investigated. Finally, the blast load mitigation factors are proposed and their empirical model are established as a function of scaled distance Z, hanging slab thickness T and hanging standoff distance D.

Automated summary

This study proposes the concept of using a hanging granite slab to mitigate blast loads on reinforced concrete columns. A finite element model is established to simulate the interaction between the blast wave and the dry-hanging granite slab, revealing the protection mechanism of the RC column. The influences of slab thickness and hanging distance on blast mitigation are investigated. Blast load mitigation factors and their empirical models are proposed as a function of scaled distance, slab thickness, and hanging standoff distance.