Response of steel fibre reinforced concrete structural elements under high rate loading

Abstract

The work presented in the subject Thesis investigates experimentally and numerically the potential benefits stemming from the introduction of steel fibres into the concrete mix in order to enhance the material properties of structural concrete and improve the response of RC structural elements under static and high rate (impact) loading. The effect of a number of parameters associated with the fibres used (e.g. aspect ratio and volume fraction) on the exhibited structural response is studied experimentally, by carrying out a series of drop-weight testing on RC beam specimens (with and without steel fibres being introduced into the concrete mix), and numerically, through the use of dynamic Nonlinear Finite Element Analysis (NLFEA). The investigation mainly focuses on studying how certain aspects of the behaviour exhibited by the beam specimens under impact loading are affected from the use of steel fibres. The use of steel fibres, at different volume fractions, results in increase of load carrying capacity and energy absorption of the structural elements under impact. The deflection at the beam mid-span also increases compared to the RC case indicating the ductility provided by the steel fibres. The extent of the effective length around the point of application of the impact load also increases due to the addition of fibres.