Cracking behaviour of two-way reinforced concrete (RC) slabs supported on beams

Abstract

Two-way slabs are commonly used in Reinforced Concrete (RC) structures to resist gravity and lateral forces. Walls or RC beams and columns typically support these slabs. When designing slabs using the limit state method, strength and serviceability criteria must be met. Even though current codes have established design methods for strength limit states, they lack well-established design methods for serviceability limit states, particularly crack width calculations in two-way slabs. Although a few studies from the literature have examined the cracking behaviour of RC two-way slabs in scaled specimens, those that investigate RC two-way slabs supported on beams have not yet been reported. This paper delves into the complete cracking behaviour of two-way slabs using an experimental investigation on four prototype RC two-way slab systems supported on beams, with varying slab thicknesses and reinforcement spacing. The study demonstrates that the cracking behaviour of RC elements under two-way bending differs significantly from that under one-way bending. The current research thus reveals the need for the development of a different analytical expression for crack width estimation in two-way slab systems. The findings of this research work could be valuable as an input parameter in developing code provisions for crack width calculation in two-way slabs.