Effect of Construction Type on Structural Behaviour of R.C Bubbled One-Way Slab

Abstract

Using Bubbles in the slab is a revolutionary method of eliminating concrete from the middle of conventional slab as this concrete does not perform any structural function, thereby dramatically reducing structural dead weight. This research presents experimental study to investigate the effect of construction type on the strength and behaviour of bubbled one-way slabs. The experimental program consists of testing four slabs with dimensions of 1850mm×460mm×110 mm. One1of the tested slabs was conventional slab (without bubbles), two bubbled slabs with different types of construction (simple and filigree bubbled slabs) and the remaining one is filigree bubbled slab strengthened with steel cage. The bubbles were made of recycled plastic balls. The experimental results show that the stiffness reduction factor for all the bubbled slabs was (0.87), this leads to decrease the ultimate strength of bubbled slabs and to be smaller than that of the solid slab by 4.4% 69% and 1.7% respectively. Also an increase in deflection at yield load (∆_y) by about (10% to 12%), at the same time the crack load is found to be decreased by (13% to 40%). The simple bubbled slab is more efficient when compared with filigree bubbled slab. Also the results show that the use of steel cage in filigree bubbled slab gives an increase in the ultimate load by 69% and an increase in the ultimate deflection by about 77% when compared with filigree bubbled slab without steel cage.