Behaviour of short-fibre-reinforced composite in bending shear

The most important parameters studied in the analysis of short-fibre-reinforced concrete (SFRC) are the tensile and flexural strength as these parameters predominantly dictate the behaviour of the composite. Studies regarding shear behaviour receive comparatively lesser attention, but knowledge of the stress-strain history under shear is important in order to understand the behaviour of a beam under bending and that of a structure under the combined loading action that accompanies shear. There have been many studies focusing on the semi-empirical relationship for peak strength of SFRC, but literature addressing full analytical shear stress-strain history prediction is scarce. An analytical model is proposed herein for predicting the analytical stress-strain history of the composite in web-shear. The formulation is developed in a composite material approach by employing basic micromechanics to describe the phenomenon in terms of the constitutive properties of the fibre, matrix and fibre matrix interface and their proportioning. The validity of the proposed analytical model was compared with the results of an experimental study and the existing model for aspect ratio in the range of 40 to 160 and was found to be in good agreement.