A Comparative Evaluation of Geopolymer, Conventional and GFRP Retrofitting Techniques in Augmenting Seismic Robustness of RC Structures

The requirement of retrofitting an existing old structure, rendered structurally unsafe (based on its structural health assessment) is observed to be a major challenge faced by engineers as it necessitates comprehensive and complicated repair procedures.It was further seen that during the earthquake, the main reason for failure of any structure was the failure of its beam column joints, thereby making it essential to strengthen them specifically.Until recently, the two most common methods for strengthening defective RC beam-column joints were concrete jacketing and steel reinforcement.Geopolymer and Fiber reinforced polymers, such as Carbon Fiber Reinforced Polymer (CFRP), Glass Fiber Reinforced Polymer (GFRP), and aramid FRP have recently emerged as new techniques for reinforcing the beam-column junction.In this study, using ANSYS Workbench 16, FEM analysis of T joints is carried out for comparative analysis of three retrofitting methods: Geo-polymer-based retrofitting, Conventional retrofitting, and retrofitting using GFRP.For this study, an existing G+3 RC building (1984 vintage) was chosen.To identify the critical joints of the building, its performance under static and seismic loading conditions was analyzed using STAAD.Pro and subsequently the retrofitting analysis of the critical joint was carried out by considering both the ends of column as hinged.Static load was applied at the free end of the cantilever beam to achieve results for key property attributes, such as deformation, equivalent stress and equivalent strain.The paper elucidates the material properties, application methodologies, and interaction with RC structures that make these techniques viable for seismic retrofitting.