CO2 Emissions in Structural Applications: Comparative Study of GFRP and Steel in Structural Components and Systems

Fiber-reinforced polymer (FRP) composites, such as glass fiber-reinforced polymer (GFRP), are increasingly considered viable substitutes for conventional construction materials like steel and concrete. Nevertheless, a knowledge gap remains in assessing the sustainability performance of FRPs under practical loading conditions compared to conventional materials for various structural applications. This study aims to evaluate the carbon dioxide (CO2) emissions of GFRP relative to steel across various structural components and systems. The analysis utilized total CO2 emissions and unit performance measures such as unit service life and unit volume CO2 emissions. A sensitivity analysis was also conducted to represent variations in primary input data, ensuring more comprehensive and robust comparison results. Results indicate that GFRP generally produces lower total CO2 emissions than steel in most structural applications, with its sustainability becoming more apparent over the service life of these structures. Unit life-cycle CO2 emission ratios show that the GFRP structural components and systems are more advantageous than steel from a long-term perspective. While the GFRP-to-steel unit volume CO2 emission ratios highlight GFRP’s sustainability, comparisons should consider material use efficiency, transportation, and space optimization, with meaningful results only when GFRP and steel volumes are similar. The sensitivity analysis further supports the sustainability of GFRP across most structural components and systems compared to steel. This study advances the understanding of GFRP’s performance regarding CO2 emissions through the holistic approach used to address the research gap. The data-driven outcomes, including GFRP-to-steel ratios for total CO2 emissions and unit performance, provide explicit insights for engineers and designers employing GFRP in infrastructure.