Steel FRC slab in compression in composite steel‐concrete frame joints

Abstract

AbstractThe objective of the research is a steel fiber‐reinforced concrete slab in compression in a composite frame joint. EN 1998‐1 relates only to composite joints with common concrete slab. This standard prescribes two mechanisms: mechanism 1 acts in the concrete slab with a concentrated compressive force on the column flange; mechanism 2 consists of struts and tie model, where concrete struts compress the concave parts of the column cross‐section. By these mechanisms, it is prescribed inaccurate formula for the effective width calculation of a common concrete slab in compression in the nodal zone, as the standard procedure does not consider the contribution of the confinement effect to the resistance of mechanism 1. Mechanism 1 represents a direct bearing of the concrete slab against the column flange. There is a concrete slab in compression confined by transverse reinforcement, slab continuity around the column flange and friction on the column flange. Moreover, some publications describe different inclination of the concrete struts of mechanism 2. The resistance of mechanism 2 significantly depends on this inclination. The aim of this work is to derive a more accurate formula for calculation the effective width of the steel fiber‐reinforced concrete slab in compression in the nodal zone. Experiment with real‐sized isolated composite joint, validation of ATENA numerical models and parametric study of composite joints with fiber‐reinforced concrete slab are the main steps of this research.