Design-Oriented Comparison of Reinforced Concrete Slab Systems for Residential Buildings in Kuwait

This study compared six reinforced-concrete slab systems for a four-story residential building in Kuwait to identify priority-dependent performance trade-offs.

Six ETABS models represented one-way slabs with beams in the x- and y-directions, a two-way solid slab, and three flat-slab configurations. Models shared geometry, materials, supports, loads, and shear walls; member sizing followed ACI 318-19, and loading followed ASCE/SEI 7-16. Outputs comprised reinforcement and concrete quantities, structural weight, concrete-and-reinforcing-steel material cost, material-associated embodied CO₂, and comparative vertical natural frequency. A CRITIC-weighted multi-criteria analysis ranked alternatives across material efficiency, cost, embodied CO₂, and frequency; sensitivity scenarios tested priority changes.

The y-direction one-way slab required the least reinforcement (26,780 kg), had the highest vertical natural frequency (6.40 Hz), and ranked first under CRITIC and equal weighting. The drop-panel flat slab without edge beams had the lowest concrete quantity (298.39 m³), structural weight (7,161.37 kN), material cost (12,992.87 KD), and material-associated embodied CO₂ (233,906.41 kg), but the lowest frequency (4.86 Hz). It ranked first in the material, cost, and emissions priority scenario.

Results reveal a case-specific trade-off between material-based performance and vertical modal response. Natural frequency alone does not establish vibration acceptability.

For this case, the y-direction one-way slab was the highest-ranked overall compromise under CRITIC weighting; the drop-panel flat slab without edge beams was preferable under material-, cost-, and emissions-focused priorities. No system was universally optimal; selection should reflect project priorities and assessment boundaries.