BEHAVIOUR OF REINFORCED CONCRETE T-BEAMS IN SHEAR.

It is shown by experiment that the shear resistance of T-beams with shear span-to-depth ratios greater than 2. 5 is provided by the flange and not, as widely considered, by the web. Such behavior is in compliance with the concept that shear capacity is associated with the strength of the region of the path along which the compressive force is transmitted to the supports, with the region of the beam below the neutral axis making an insignificant contribution. The high loadcarrying capacity of the compressive zone appears to be related with the triaxial stress conditions that exist there. It is demonstrated that there is already available an empirical design formula which is in compliance with the concept of the 'compressive force path' and, unlike the formulae recommended in Codes of Practice, provides realistic predictions of both shear capacity and location of shear failure.