Post-elastic behaviour of ground-floor slabs. Part 2: Fabric-reinforced concrete slabs

Abstract

Ground-floor slabs (GFS) are being increasingly designed to carry loads beyond their elastic limit, particularly by means of classical plastic analysis. To this end, a study has been carried out to investigate the inelastic behaviour of both plain and fabric-reinforced concrete GFS. The results of the study on plain-concrete GFS were reported in the first of a set of two papers, while the present, second paper is devoted to the research work carried out on fabric-reinforced concrete slabs. Both papers aim at advancing the understanding of the behaviour of these slabs by means of non-linear finite-element analysis (NLFEA) that employs a constitutive model which is based on experimental data on concrete behaviour under triaxial states of stress. Similarly to the findings for the plain-concrete GFS, and with design rationale in mind, a new performance-based (PB) definition for the failure criterion is also proposed for fabric-reinforced GFS, which takes into account the all-important slope condition (i.e. the effect of structural loading on flatness and levelness of the slab). Finally, NLFEA-based design recommendations are made on the effect of the steel reinforcement on the strength and serviceability of fabric-reinforced GFS, including also recommendations on the appropriate location (i.e. top or bottom) of the steel in order to achieve a balanced strength throughout the slab. The present research represents a considerable improvement on existing classical plastic analyses as the latter provide no information on deflections and slopes.