4.4. STRUCTURAL UP-GRADING OF REINFORCED CONCRETE BUILDINGS IN SEISMIC ZONES WITH MODERN TECNIQUES USING CARBON FIBRES

The correct approach to the precautionary structural up-grading of reinforced concrete building in seismical zones prescribes the previous careful analysis of the strength and stiffness of the bearing elements (pillars, beams and, if present, bearing walls), the re-balancing of their parameters and the improvement of the ductility of all said elements by means of adequate technologies.

Through a qualified and in-dept design based on the "limit states analysis", as prescribed by Eurocodes, and the use of the innovative carbon fibers, it is possible to reach the required safety level and prevent the collaps of the structures (and the possible loss of human beings) by causing the bearing elements to absorb the energy released by earthquakes, although accepting the damages to the structures, even the very serious ones, without collapsing.

This principle is graphically exposed in Picture 11 showing that the behaviour of the structure under increasing loads up to F2 maximum, which can be assessed from the ordinate axis, can be represented either by the OB segment or by the OAC broken line.