A comparative review on bubble-voided reinforced concrete slab – An innovative concept for lightweight concreting

Abstract

The bubble-voided reinforced concrete (RC) slab is a relatively new concept of light-weight concreting, introduced to the industry. In this concept, the consumption of unnecessary concrete between the tension zone and the neutral axis, inside a RC slab (one-way or two-way), can be avoided by the introduction of voids at that very zone in the form of hollow plastic bubbles. The bubble-voided slab is lightweight in comparison to the solid slab, and self-weight can effectively decrease upto 30% to 40%, through the application of spherical voided-formers. Although, the bubble-voided slab’s load capacity is slightly less, compared to the equivalent solid slab. But, unlike the hollow-core slab, bubble-voided slab performs well against bi-axial loading. As, the concrete consumption is less in bubble-voided slabs, so less amount of cement needs to be manufactured, and, this way, the bubble-voided concreting method can indirectly be beneficial in reducing the Carbon-Di-Oxide (CO2) emission in the atmosphere. The bubbles can be made of plastic waste, which is an innovative way to recycle that waste plastic to use in industry, and, also reduce plastic wastage from the nature. So, it can be understood that bubble-voided concreting is very much eco-friendly. The present authors have explored through the evolution in the researches on the bubble-voided concrete slab, and, discussed about the critical findings of previous researchers. A comparative discussion is also, presented in this study on various input parameters and load vs deflection curves presented in previous studies. The comparisons showcase that the depth of slab (DS), grade of concrete, and, percentage of void, are the key factors which influence the load vs deflection behaviour of bubble-voided RC slabs. Future scopes in this field of study are identified, such as, studies on the effect of thermal loading, impact loading, and, cyclic loading on the bubble-voided RC slabs.