A Comparative Study of Analysis and Design of Flat Slab and Hollow Block Slab and construction cost of RC Buildings

Abstract

Concrete-framed buildings with reinforcement are commonly favored over other building types in Sudan. These buildings often utilize flat and hollow block slabs. When designing these structures, it is necessary to determine the most suitable slab type that can withstand both gravitational and lateral loads while keeping costs to a minimum. However, the selection of slab type is often overlooked by designers, who tend to focus more on other structural elements like beams, columns, and walls. As a result, the structural contribution of floors in building design is often not adequately assessed. It is crucial to thoroughly examine this aspect from the very beginning of the design process. This study aims to evaluate the effects of two types of slabs on multi-story reinforced concrete buildings, exploring their structural behaviors in an effort to reduce overall costs. A total of 18 structural models were created, analyzed, and designed according to the BS 8110 and UBC97 standards. In these analysis, the important factors taken into account were the type of slab system (either flat or hollow block), the number of floors (10, 15, and 20), and the span length (5, 7.5, and 9 meters). The buildings were assumed to be residential buildings located in a seismic zone 2A in Atbara, Sudan. The results showed that buildings with flat slabs generally have longer periods, higher base shear forces, and larger rooftop displacements compared to those with hollow block slabs. The hollow block slab consistently emerged as a cost-effective option, while the flat slab proved to be a less economical choice