Composite Slab Made from Precast, Pre-Tensioned Concrete Planks and Lightweight Concrete

Abstract

New architecture trends consisting of designing large, space-free spaces, force structural engineers to develop new solutions that allow them to bridge large spans with relatively small thicknesses. Therefore, structural engineers are looking for new solutions and improvements to existing solutions both in the field of post-tensioned slabs as well as pre-tensioned, precast elements. In particular, precast concrete manufacturers offer many solutions of partially or fully precast slabs, each of which performs better in some situations and worse in others. The advantages of precast structures are increasingly noticed by all participants of the construction process, including producers who want to meet the requirements of the construction market for developing newer, better and more hybrid solutions, so that competition with traditional concrete technology is possible. In the field of the optimisation of existing precast slab solutions in Poland, work has been undertaken in recent years on the use of pre-tensioned concrete planks proposed a few decades ago as shuttering elements, which include a tension reinforcement zone in the slab. The author of this work proposes making a slab made of pre-tensioned concrete elements of low thickness for use as shuttering for reinforced concrete made of lightweight concrete, which is lighter than conventional, traditional concrete by around 30%. The resulting composite slab of precast elements would be relatively cheap with regard to transportation and assembly, which makes them competitive for the popular ribbed floor structures usually used in houses, whilst at the same time having the advantages of solid slabs, such as good mechanical and acoustic properties. In addition, they also compete with each other with regard to pricing, which is why they could be a good alternative for investors to choose. The work presents the concept of such a slab and an example of analysis.