Nonmetallic fabric-reinforced geopolymers for rehabilitation of reinforced concrete beams with corroded stirrups

Corrosion of steel stirrups in reinforced concrete (RC) structures is a common durability problem that could result in a catastrophic failure without warning. Conventional repair via RC jacketing is labor-intensive and often vulnerable to the same deterioration mechanism. An innovative, corrosion-resistant, and sustainable alternative solution for rehabilitation of RC beams with corroded stirrups was developed and implemented in this study. The newly proposed repair option involves the use of nonmetallic fabric reinforcement embedded into a geopolymeric matrix. Ten structural tests were conducted on shear-critical RC beam specimens with corroded stirrups. The shear behavior of the beams repaired with the proposed fabric-reinforced geopolymeric matrix (FRGM) option was compared to that of similar beams repaired with fabric-reinforced cementitious matrix (FRCM) composites. Test results showed that the shear strengths of the beams with 15 % and 50 % stirrup corrosion were 12 % and 34 % lower than that of a control beam. The newly proposed FRGM repair option resulted in up to a 54 % improvement in the shear capacity and successfully recovered the original shear strength of the control beam. The shear strengths of the beams repaired with FRGM were 83–100 % of that of their counterparts repaired with FRCM composites. Such research findings demonstrate the feasibility and viability of using the geopolymeric matrix as a sustainable alternative to the commercial cementitious mortar to produce cement-free composite-based solution for rehabilitation of RC beams with corroded stirrups.