A. Sheikhalishahi, B. Ahmadi-Nedushan,
Volume 15, Issue 4 (11-2025)
Abstract
This study presents a cost optimization approach for simply supported one-way ribbed slabs, with the primary objective of minimizing concrete and reinforcement costs. A Genetic Algorithm (GA), implemented in MATLAB, is utilized to address this optimization problem. The optimization model incorporates seven discrete design variables: rib dimensions (spacing, bottom/top width, and height), topping slab thickness, flexural reinforcement diameter, and concrete compressive strength. For validation, an initial optimization based on ACI 318-08 with six variables demonstrated a 3% cost reduction compared to established algorithms. To ensure practical relevance, subsequent optimizations incorporated actual market conditions utilizing the 2025 Iranian Building Construction Price List. Transitioning to ACI 318-19 resulted in a 10% increase in optimal cost relative to ACI 318-08, primarily due to stricter shear strength provisions. To mitigate this increase and enhance design efficiency, concrete compressive strength was introduced as a seventh design variable. This expanded optimization was evaluated across spans ranging from 5 to 8 meters, yielding a further 4.4% cost reduction for a 6-meter span. Conclusively, the results demonstrate that the strategic application of higher-strength concrete, informed by real-world market prices, significantly reduces the overall cost of one-way ribbed slab construction.
