An Analytical Study on the Flexural Behavior of RC Beams Strengthened Using Multi-layer Prestressed CFRP Sheets

초록

In this study, the flexural strengthening effect of reinforced concrete (RC) beams using two layers of prestressed carbon fiber reinforced polymer (CFRP) sheets was considered. A commercial finite element analysis software, ATENA 3D, was utilized to construct the CFRP-strengthened RC beams. The main variables in the analysis included the prestressing level, combinations of prestressing, and the timing of reinforcement application. The ultimate load, ductility, material deformation, and crack patterns of each specimen were compared. From the analysis, the maximum strength of the specimens was similar, regardless of the prestress level applied to the carbon fiber. Although higher prestressing levels enhanced the reinforcement effect, the specimens exhibited brittle behavior. In contrast, specimens reinforced with both prestressed and non-prestressed CFRP sheets, demonstrated a reinforcement effect similar to that of specimens with two layers of prestressed CFRP sheets, but with ductile behavior. After the application of the initial load, specimens reinforced with a combination of prestressed CFRP sheets showed an increase in maximum strength compared to the control specimen, along with reduced material deformation, deflection, number of cracks, and average crack width. Additionally, the camber effect that occurred immediately after reinforcement contributed to crack reduction, thereby verifying the superior crack control of the reinforced specimens. © 2024 by Korea Concrete Institute.

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