Geopolymer-based system to retrofit RC beams with novel Inhibiting-Repairing-Strengthening (IRS) technique

The work aims to experimentally and theoretically investigate the structural performance of an innovative solution, alternative to Externally-Bonded (EB) technique, for retrofitting of Reinforced Concrete (RC) structures with deteriorated cover concrete and/or corroded bars: Inhibiting-Repairing-Strengthening (IRS) technique. It consists in the installation of a stainless steel fabric in the cover concrete, restoring the latter with a geopolymeric matrix (Steel Reinforced Geopolymeric Matrix, SRGM). The proposed IRS solution reduces the time and costs of intervention. Two groups of large-scale RC beams were strengthened with IRS-SRGM and EB-SRGM systems and tested under four-point bending. Test results showed that the IRS-SRGM system provided a good performance increasing the load carrying capacity up to 30% with a limited loss of ductility compared to the unstrengthened RC beam. Furthermore, a theoretical prediction of the tested beams and analytical/experimental comparisons were carried out.