Full-scale testing of steel fibre reinforced concrete flat slab

Abstract

Introduction.  The use of steel fibre reinforced concrete (SFRC) in flat slabs without capitals remains limited despite its potential to improve crack resistance and reduce reinforcement complexity. This study investigates a slab with combined reinforcement, integrating steel fibres with localized bar reinforcement. Aim.  To experimentally verify the structural performance and load-bearing capacity of a column-supported SFRC flat slab with combined reinforcement through full-scale testing. Materials and Methods.  Full-scale tests were carried out on a slab of a local wastewater treatment facility at the age of 30 days. The concrete class was B30, and Hendix® Prime 75/52 steel fibres were used at a dosage of 70 kg/m[3] . The load was applied stepwise at the slab centre over an area of 1.5 × 3.0 m. The maximum load reached 15.5 tonnes-force (3.45 tonnes-force/m[2] ). A finite element model and elastic analysis at the ultimate limit state were used to ensure equivalence between test and design loading conditions. Results.  The slab exhibited elastic behaviour up to approximately 65 % of the maximum load. Further loading resulted in stiffness reduction and nonlinear deflection growth, reaching 2.10 mm at peak load. No visible cracking was observed. Residual deformation after unloading was 0.14 mm. Conclusions  . The results confirm the feasibility of using SFRC with combined reinforcement in flat slabs. The proposed solution ensures adequate load-bearing capacity and crack resistance while reducing conventional reinforcement, indicating strong potential for practical implementation.