Safety and Economy in the Design of Reinforced and Post-tensioned Slab Systems Using IS, BS, and ACI Standards

An office floor with a typical grid size of 10.8 × 8 m in a multistory building was considered for design with flat-slab, flat-plate, and beam-slab systems. In all cases, both RC and post-tensioned systems were used for the comparison of structural performance and cost together with safety. The slab systems were designed using three different codes of practice: Indian Standard (IS), British Standard (BS), and American Concrete Institute (ACI) standards. From the cost analysis, it is observed that the post-tensioned flat-slab system provides better cost reduction of approximately 16.5 and 20% in the case of IS and BS standards, respectively. In the case of ACI standards, the RC and post-tensioned flat-slab systems yield 17.7 and 12.5% cost reduction, respectively. From the study, it was concluded that the post-tensioned flat-slab system using ACI standards is considered to be durable because the tensile stress is restricted and designed as an uncracked section, whereas the IS and BS allow 0.2-mm crack width.