NUMERICAL EVALUATION OF SLAB THICKNESS EFFECT ON THE IMPACT BEHAVIOR OF CONCRETE SLABS REINFORCED WITH CFRP BARS

Mohammed A Dheyab,Mu’Taz K Medhlom

doi:10.31272/jeasd.conf.2.4.6

Abstract

Theoretical investigation of the nonlinear behavior of concrete slabs reinforced with CFRP bars subjected to a single impact load is presented in this paper. For predicting the impact load on a concrete slab, there are several methods, some of which are impractical or prohibitively pricey; however, due to significant technological advancements, simulation methods instead of experimental approaches have become common methods and a cost-effective matter for developing detailed responses. The purpose of this paper is to numerically investigate the effect of slab thickness on the impact response of concrete slabs reinforced with (CFRP) bars when subjected to a single impacting load, so as to well understand their behavior which are considered modern topics and rarely highlighted. Three specimens (1800×1800) mm, with three thicknesses 80, 130 and 180 mm, simply supported by their corners, have been modelled, one reference specimen of 130 mm thickness. The reference slab numerically validated with an experimental work from literature under dropping-weight of 150 kg, it was a flat-nosed rigid steel (300*300*700) mm projectile, used to apply impacting load, which is falling freely from a height of 3.26 m. To assess slab behavior, impact force-time, displacement-time and reaction force-time histories had been plotted and discussed. The analytical results showed that slab thickness is a control factor and better performance in slabs reinforced with CFRP bars, can be achieved by increasing slab stiffness via its thickness increase.

Highlights

There is still a lack of knowledge about the dynamic behavior of reinforced concrete (RC)structures, where they are analyzed and designed currently on the basis of their static response [1]
Reinforced concrete structures may be subjected to a variety of dynamic loads during their service lives, including seismic, rocks’ fall, blast loads and accidents can all cause impact loads
It is shown that the increasing slab of thickness 38.46% in order to make it 180 mm, Impact force increased 48.1% with a shorter duration than R1

Summary

Introduction

There is still a lack of knowledge about the dynamic behavior of reinforced concrete (RC)structures, where they are analyzed and designed currently on the basis of their static response [1]. Reinforced concrete structures may be subjected to a variety of dynamic loads during their service lives, including seismic, rocks’ fall, blast loads and accidents can all cause impact loads. As a result of these types of dynamic loading, a structure's loading rate can change, causing the structure to respond dynamically in a different way than it did statically before. A structural member that fails under static load but fails in shear when the loading rate is increased, for example. It has been found that reinforced concrete members can withstand higher loads as the loading rate increases. The main reasons for these differences are inertial effects, stress wave propagation, and strain rate effects on the constitutive properties of reinforcement and concrete [2]. Depending on Bischoff and Perry [3], induced and blast loadings generate high strain rates (100/s to 103/s)

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