Experimental Testing of a Complex-Geometry Floor Slab Manufactured Using 3DCP Technology (2025-11)¶

This paper presents the results of an experimental investigation of a thin-walled reinforced concrete slab of complex geometry manufactured using 3D concrete printing (3DCP) technology. The aim of the study was to evaluate the stress–strain behaviour and flexural stiffness of an optimized slab whose internal structure was formed according to the principles of rational cross-sections and topology-based shape design. The tested slab, measuring 2200×2200 mm, incorporated a system of curved ribs printed in 20-mm layers, forming a cellular load-bearing pattern with enhanced material efficiency. The experimental program was carried out on a rigid spatial steel testing frame with full perimeter support. The load was applied incrementally by placing cast-iron calibration blocks (21 kg) and heavy concrete FBS blocks weighing 518 kg, which ensured an equivalent uniformly distributed load. A total of 12 loading stages were performed with a 15minute stabilization period at each step, reaching a maximum surface pressure of 25.06 kN/m². Vertical displacements were recorded using three highprecision dial gauges (0.01 mm accuracy), while local strains were measured by ten strain gauges with a 20 mm base installed at characteristic locations on the upper and lower surfaces of the slab. The obtained results showed that the slab exhibited linear-elastic behaviour throughout the entire loading range. The maximum central deflection reached 2.06 mm, and after complete unloading decreased to 0.63 mm, confirming a significant proportion of recoverable deformation and the absence of damage. Strain gauge readings indicated a uniform development of compressive and tensile strains consistent with the bending moment distribution, with no evidence of localized stress concentrations. The strain curves contained no sudden jumps or anomalies, indicating the integrity of interlayer bonding and the absence of any signs of structural degradation. The findings confirm the effectiveness of 3DCP technology for manufacturing load-bearing floor slabs with complex internal geometry. The tested element demonstrated high stiffness, reliable structural performance and highlighted the promising prospects for the development of topologically optimized reinforced concrete structures in modern construction.