Response of low-percentage FRC slabs under impact loading: Experimental, numerical, and soft computing methods

Application of fiber reinforced concrete (FRC) has been increased in the past decade due to its enhanced structural performance. Therefore, it is important to fully characterize its static and dynamic behavior under different loading scenarios. In this paper, the effects of low-percentage steel fibers with four different fiber volume is investigated on the dynamic responses of concrete slabs. First, a series of experimental tests are conducted. Next, the results are used to validate a nonlinear finite element model under impact loading. Finally, a large dataset of numerical simulations are developed using appropriate design of experiments, and four soft computing techniques are used to predict the target responses. The findings show that application of low-percentages fiber increases the acceleration response of the concrete slabs subjected to impact load, on the average of 102%. The slab's stiffness increases with an increase in fiber percentage. The dominant frequency, the damping ratio, as well as the slab's cracking pattern, and the failure modes indicate that FRC slabs are stiffer than conventional RC specimen. The numerical simulations reasonably estimate the maximum acceleration. Outcome of the predictive meta-models can be used to estimate the dynamic behavior of similar slabs with no additional experimental and numerical costs.