Strengthening prefabricated reinforced concrete roof beams that are damaged by corrosion of concrete and reinforcement

In this article are analyzed different methods of strengthening reinforced concrete structures as ceilings and coverage. And there are also structured methods and the principles of their execution. In this article are described in detail and are shown graphically the methods of strengthening prefabricated reinforced concrete I-beams of coverage (its span is 12 m), which were in accident technical state at the moment of examination. The compression and tensile areas of concrete in structures were completely destroyed by corrosion, and furthermore the joint work of normal concrete and pre-stressed reinforcement was not ensured. In general, the examined methods of strengthening concern the reinforced concrete structures, where the strengthening elements come to work in conjunction with the existing concrete and reinforcement. Presented method consists in total forces transfer on strengthening elements, i.e. concrete and reinforcement of the existing reinforced concrete structures of floorings are completely excluded from work. (paper)