POST TENSIONED SLAB

The use of post-tensioned reinforcement to construct floor slabs can result in thinner concrete sections and/or longer spans between supports. Designers commonly take advantage of this method to produce buildings and structures with clear open spaces allowing more architectural freedom. Reducing the thickness of each structural floor in a building can reduce the total weight of the structure and decrease the ceiling to floor height of each level. In belowgrade structures, this can mean less excavation, and in abovegrade structures, it can mean a reduced overall building height. In areas with building height restrictions, saving 8 to 12 inches (or more) of height on each level can add up by the time you reach 10 or 12 levels. The use of post-tensioning commonly is applied to “flat slab” or “flat plate” construction in multilevel structures. The longer spans cut down on the number of columns required and give the designer more freedom to layout the building. Even longer spans can be achieved by using beam and slab construction, such as in a parking structure where typical post-tensioned beams can span 60 to 65 feet.