Experimental tests of RC beams strengthened with composite materials using IPN water-based resins

Composite materials have been used for both the structural strengthening of single RC elements and the complete retrofit of buildings for over 20 years. The composites mainly used are based on carbon, aramid or glass fibres, laminated with epoxy resins matrices. As known, one of the limitations of epoxy resins is the poor fire resistance of the matrix, and this can often influence how composite materials are used in building construction. In this research, an experimental investigation was carried out on reinforced concrete beams strengthened with unidirectional carbon fibre reinforcements and two-component resins of the Interpenetrated Polymer Network (IPN) water-based type that have greater thermal resistance than epoxy resins. In the experimental campaign, several beam specimens were reinforced using different strengthening configurations for bending and shear. In particular, the results obtained for the beams strengthened using water-based resins were compared with those for equivalent specimens strengthened with epoxy resins. The results showed good mechanical properties for the reinforcements with the IPN matrix, where the values of the collapse load were similar to those of the reinforcements with epoxy resins.