The basis of KUB-2.5 structural system is the original joint of two main elements – a floor slab and a column. The column is connected with the reinforcement frame of the floor slab by means of an insert – a steel manacle ring of a special structure.

The building’s/structure’s frame erected in the system of the structural frame without collar beams is a tridimensional precast structure. Columns perform as frame stands and floor slabs function as collar beams; ties or shear walls are used as rigidity elements. Any stair cases, ventilation units, lift shafts which are put into production as local fabrication plants can be used.

External walls do not bear any loads thus it is not required to set up foundations for them, they should not be designed as strong as they are designed in the buildings of unframed type. Load on the frame’s bottom is 25% less than in the cast-in-situ buildings. Despite ground conditions foundation area which his required for forces distribution in the bottom of the superstructure, which has been erected in KUB-2.5 structural system, always remains minimal as frame’s dead load in minimal because all sections are optimized.

Structures of the frame without collar beams are meant for exploitation in different regions where seismicity reaches 7-9 points.

Strength of KUB-2.5 structures was proved with technical calculations and numerous tests:

• KUB structures were considered by the Scientific and Technical Council of the State Committee of Architecture of Gosstroy of USSR and were recommended for application via letter No. ИП-7-3691 dated 19 September 1986;
• KUB frame was recommended for applications by Kucherenko’s Central Scientific and Research Institute of Construction Structures of Gosstroy of USSR (conclusion dated 15 March 1990);
• Laboratory of dynamic tests of the Central Scientific, Research and Design Institute of Residential and Public Buildings headed by GN Ashkinadze.

More than thousand of KUB-system Projects have been constructed in Russia and worldwide in the recent years.