Comparison and Examination of Bubble Slabs Versus Solid Slabs

Abstract

Among the modern technologies in the field of lightweight construction, the implementation of lightweight reinforced concrete slabs by creating spherical voids in their core is notable. This system, commonly known as bubble slabs, differs from bubble slabs due to its nature and load transfer mechanism (two-way) and can serve as a suitable replacement for solid or conventional two-way slabs. This research examines this type of slab and compares some of its features using laboratory tests and manual or numerical calculations with slabs of the same thickness. The results indicate that the compressive strength of the bubble system is nearly the same as that of the conventional system, with the bubble system exhibiting approximately 5% lower compressive strength. This difference is due to the smaller vertical area of the bubble sample compared to the vertical area of the solid sample. And the deflection of these slabs is approximately similar, and their shear capacity is 73% of the shear capacity of the corresponding solid slab. Furthermore, calculations show that the moment in bubble slabs is about 5% to 10% less than that in solid slabs, and this reduction in maximum moment is due to the removal of inactive concrete from the slab.