Trade Journals for the Concrete Industry

Part 1 of this paper looked at the historical development of floor construction methods covering the long period of time from their beginnings up to today. It should, however, be borne in mind that reinforced concrete beams dominated floor construction for almost 100 years, despite the fact that flat floors had already been invented approximately 30 years after the first reinforced concrete beams. Due to high material costs, flat floors could not initially make the breakthrough that ought to have been possible from a technical point of view. Once new types of reinforcing elements, such as e.g. stud rails and prestressed steel, started to be employed, the success of flat floors and, in particular, their utilisation for large span widths was unstoppable. Flat floor designs gave rise to many further developments for improving cost-effectiveness in construction work. Among these can be found: floor manufacturing with semi-finished precast, the many varieties of formwork systems, an abundance of reinforcing elements for safeguarding shear loading capacity, and the development of unbounded prestressing with the aid of monostrands that will have already been protected against corrosion at the production facility. These developments, which have only occurred during the last 40 years, are indicative of the high technical level with this flat floor construction method. The following will describe what new requirements must be met by floor systems today and how flat floors have turned into multi-functional floor structures.