New technology has been introduced for the Beirut Terraces Project in order to achieve a light weight slab (U-Boot system for reinforced concrete slabs). This innovative system has been implemented successfully for the first time in Lebanon.
The U-Boot is a modular element made of recycled propylene formwork used in all applications that require a structural plate, together with the need to use less concrete, and therefore, for a lighter structure. U-Boot is an ideal solution for creating slabs with a large span and/or great load-bearing capacity. It is particularly suited for structures that require considerable open spaces, such as executive, commercial and industrial buildings as well as public, civil and residential structures. With its high inertia level, this building system makes it possible to build large-scale constructions with a distinct cost advantage compared to traditional building solutions and in direct completion with prefabricated structures. It makes it possible to more irregularly distribute the pillars, as beams do not need to be created. In the case of yards that are difficult to access or restructuring work, U-Boot, due to its stack ability, modularity, lightness and maneuverability, can be used to make horizontal structures without the help of handling and hoisting equipment. With U-Boot, foundation rafters can be created with a larger thickness and a reduced amount of concrete. For the concrete bed, the distribution of weight due to high inertia is rationalized in order to permit maximum stiffness and lightness for the structure which makes it possible to eliminate, wherever possible, the foundation piles.
For better efficiency and speed, MAN Enterprise is combining the U-boot with a post-tension slab 45 cm thick, with high inertia and less concrete quantity and weight. Having less material, the U-boot slab, coupled with post-tension, is more efficient than any other alternative. Furthermore, seismic forces are directly proportional to the weight of the structure, as less weight means less lateral forces.
At the same time, the post-tension reinforcement makes work faster and reduces congestion of steel rebar, thus improving vibration and concrete quality. The speed gained by the contractor increases the buffer time and the chances of finishing the project on time.