Strength and deformation characteristics of steel fibrous concrete beams

The results of an analytical investigation of the flexural behaviour of Steel Fibre Reinforced Concrete (SFRC) beams are presented. The complete response of the SFRC beams under displacement controlled static loading was obtained using nonlinear Finite Element (FE) techniques implemented with the help of ATENA 2D software. Issues relating to the behaviour of SFRC which have a direct bearing on the FE modelling are discussed with relevance to the software employed for the nonlinear analysis. Constitutive models amenable to numerical analysis for steel fibrous concrete are presented. The structural response throughout the loading regime was captured in terms of the load-deflection behaviour, which in addition to the post-peak response characterized the failure mode of the test beams. The crack patterns at crack initiation and at the end of the tests were also recorded. Experimental results from the specimens of two other investigators were used as control values for this investigation. The response of the specimens of this investigation was evaluated in terms of initial tangent stiffness, peak loads and toughness. Good match was obtained between the results from this investigation and corresponding experimentally obtained values, wherever available. The influence of the fibre content is reflected in the observed trends in peak loads, deflection at peak loads and toughness, which are in broad agreement with known behavioral patterns of SFRC.