Shear of prestressed concrete beams with steel fibres

This study outlines the details of non-linear analysis using the modified compression field theory (MCFT) of 11 shear–critical partially prestressed concrete T-beams having steel fibres over partial or full depth. Prestressed T-beams having a shear span-to-depth ratio of 2.65 and 1.59 that failed in shear have been analysed using Response-2000. Response-2000 is an implementation of MCFT within the framework of sectional analysis originally developed for reinforced concrete beams having no fibres. The modelling of the various effects of fibre in the concrete matrix using Response-2000 has been illustrated in the current study. The MCFT-based model used for the present analysis accounts for the non-linearities, such as effect of addition of fibres in the post-peak regime of the compressive stress–strain response, the post-cracking tensile stiffness and response of concrete. The load sustenance through the bridging action of steel fibres at the crack interface has been accounted for in the model. The reinforcements such as deformed bars, prestressing wires and steel fibres have been modelled discretely. The capability of the model to capture cracking behaviour, loads and deflections in various types of shear failures in prestressed concrete beams has been illustrated