Verulam

Full-scale testing of 200mm-deep floor slabs has shown that the shear transfer capacity between units depends on the development of shear friction by aggregate interlock, and on dowel action of the reinforcement in in situ concrete end beams. Interface shear stresses are in excess of working load by a factor of at least 2.15. Cyclic loading causes a degradation in shear stiffness Ks, and an increase in residual permanent deformation in the slab and in the reinforcement. Friction factors, which are in excess of design values, were the result of clamping forces generated by the axial restraint stiffness Kn, of the reinforcement. Ultimate failure was due to horizontal splitting of the in situ concrete end beams. G. Davies, K.S. Elliott and W. Omar

Empirical equations based on experimental data and suitable for design office use are presented for estimating the strength of steel fibre-reinforced concrete elements in shear. Illustrative examples and design aids are given. I.Y. Darwish and R. Narayanan