Comparison between Flat and Waffle Slabs in Terms of Behavior and Quantities

Abstract

Reinforced concrete buildings comprises majority of buildings in urban areas. In reinforced concrete slabs the major challenge occurs when high dead-weight of concrete restricts the span length and thus longer spans are not feasible with normal construction practices. It is a known fact that excellent concrete molding capability and various innovations over the past few years on maximizing the material utilization led to development of ribbed one way, two way and pre-stressed slabs. In this study a comparison of materials quantity of waffle slabs and flat slabs has been carried out. For analysis purpose slabs are modeled in computer program SAFE V.12 and the output results obtained from the analysis are compared with the manual analysis results and then used in manual design. In this study a square slab of 6×6 m panels is modeled for both waffle and flat slab under the same loading conditions and using the same construction material. The models are used to study parameters like maximum deflection, maximum bending moment and punching shear resistance. The amount of concrete and reinforcement required in slab signify the superiority of waffle slab over flat slab and consequently can be employed in various applications as an economical alternative for flat slab.