Structural Analysis Of Two-way RC Slabs With GFRP Sheets Subjected To Blast Loading Of Conventional Weapons

At present, the researches of beams and columns strengthened by Fiber Reinforced Polymer—FRP is relatively more overall, but the researches of two-way slabs is very little, let alone the structural analysis of two-way slabs subjected to the blast loading.This study deals with the structural response and ultimate resistance of reinforced concrete two-way slabs retrofitted with externally bonded GFRP. Five 1500 *1500 * 150 mm reinforced concrete two-way slabs were made of C25 concrete and two orthogonal layers of GFRP sheets. One of the slabs was used as control. Four slabs were retrofitted with GFRP sheets applied to the bottom surface. Four retrofitted slabs were subjected to various blast pressures. The blast wave characteristics, including the pressures of the blasts and impulses were measured and recorded. The central deflection and strains in the reinforcing steel and the concrete and the GFRP surfaces were also measured. The post-blast damage and mode of failure of each slab were observed. The test data and observations revealed that the slabs retrofitted with either the GFRP sheets had higher blast resistance and they generally performed better than the control slab.Theoretical analysis of the test data showed that the software LS-DYNA can predict the blast wave parameters relatively accurately and is a useful tool for estimating blast loads on structures. The dynamic analysis of the slabs was performed using a closed-form solution. When the flexural rigidity of reinforced concrete at different load levels was properly considered, the closed-form solution was able to predict the observed response of the slabs reasonably well.