Computational modeling of flat slabs: Influence of ribs and flexural reinforcement on shear strength

Abstract

A greater number of structures are being built with flat reinforced concrete slabs because they offer several advantages. However, many designers are still unsure about the type of slab that has the best structural performance and which building codes provide the best strength estimates. This study presents nonlinear computer simulations of 16 flat reinforced concrete slabs under symmetrical punching: 4 solid slabs, 4 waffle slabs with wide beams, and 8 waffle slabs with different numbers of ribs supported in the solid area of the slab. Geometric longitudinal reinforcement ratios ranged from 0.45% to 1.97%. The results showed that solid and beamed slabs are more resistant, and normative estimates overestimate their strengths, while the opposite outcome was found for waffle slabs, whose estimates provided in the codes were rather conservative. The most accurate code was EC2, followed by ACI 318 and NBR 6118.

Keywords:
Punching; Flat waffle slab; Wide beam

Graphical Abstract