Analysis and Design of Critical Floor of Commercial and Residential Building Using Conventional Slab and Flat Slab Systems: A Comparative Study

ABSTRACTThe selection of an appropriate floor system significantly influences the structural efficiency, materialconsumption, construction speed, and architectural flexibility of multi-storey buildings. This paper presents asystematic comparative analysis and design of two widely used reinforced-concrete floor systems—theconventional beam–slab system and the flat-slab system—applied to the critical GF TOP storey of a real mixeduse commercial and residential building (Project MADNAIK). Two independent three-dimensional modelswere developed in ETABS 21.0.0 under identical geometry, material properties (M25 concrete and Fe 500steel), column layout, and gravity loading. Analysis was performed for the governing ultimate combination1.5(DL + LL) in accordance with IS 456:2000. Design strips conforming to Clause 31 were employed for theflat-slab model, while the conventional model utilised a hierarchical beam–slab load path. Results indicate thatthe flat-slab system develops a maximum hogging moment approximately 2.11 times and a maximum shearforce approximately 2.63 times higher than the critical beam of the conventional system. Conversely, theconventional system exhibits a substantially higher mid-span sagging moment. Column axial loads differ byonly 3.3%. Service deflection of the flat slab remains within codal limits. Material quantification shows lowerconcrete volume but significantly higher reinforcement demand for the flat-slab alternative, offset by thecomplete elimination of beam formwork. The study demonstrates that neither system is universally superior.The conventional system offers lower peak forces and familiar detailing, while the flat-slab system provides acontinuous soffit, reduced formwork complexity, and faster construction. The quantitative force ratios,deflection data, and material quantities generated herein supply a practical, code-compliant basis for informedfloor-system selection in similar mid-rise mixed-use projects.Analysis and Design of Critical Floor of Commercial andResidential Building Using Conventional Slab and Flat SlabSystems: A Comparative Study1Ninad Pradip Chougule, 2Dr. N. S. Bembade 3Mr. Vijaykumar G. Sawant1PG Scholar, Department of Civil EngineeringPadmabhooshan Vasantraodada Patil Institute of Technology, Budhgaon, Sangli –416304, India2 & 3 Assistant Professor, Department of Civil EngineeringPadmabhooshan Vasantraodada Patil Institute of Technology, Budhgaon, Sangli –416304, India