25 years of FRP research at Istanbul Technical University

The application of fiber-reinforced polymer (FRP) composites for structural strengthening and seismic retrofitting has significantly advanced in recent decades. This study presents a com-prehensive review of FRP research conducted at Istanbul Technical University (ITU) in the last 25 years, which has closely aligned with global developments in the field. The research at ITU has focused parti-cularly on addressing the substandard characteristics prevalent in Türkiye's building stock. Investigations have spanned a wide range of specimens, from small-scale concrete prisms to full-scale three-dimensional reinforced concrete (RC) buildings. Key focus areas have included FRP applications for ductility enhancement, flexural strengthening and seismic retrofitting of structural members. Various FRP mate-rials have been examined, including aramid, glass, carbon, basalt and PET fibers. Multiple application techniques have been explored, ranging from externally bonded reinforcement to textile reinforced sprayed mortar. The findings from these extensive studies have consistently demonstrated the efficacy of FRP composites in enhancing the structural performance and seismic resilience of substandard buildings. This body of research has made significant contributions to the development of practical retrofit solutions tailored to the specific challenges posed by Türkiye's existing building stock and has broader implications for seismic risk mitigation in countries with similar construction practices.