Increase the Flexural Strength of Post-Tensioned Prestressed Concrete Beams by using Unbonded Composite Tendons (CFRP & Steel)

This paper investigates the potential of CFRP-steel composite tendons to enhance the flexural performance of prestressed concrete beams. CFRP strands offer high tensile strength, lightweight characteristics, and excellent corrosion resistance, whereas steel strands are ductile and cost-effective. The combination of these materials in composite tendons aims to optimize the structural behaviour and durability of prestressed beams. This study provides a comprehensive overview of the current state of research on the mechanical properties, bond performance, and failure mechanisms of prestressed concrete beams reinforced with CFRP-steel composite tendons. Additionally, it examined the influence of different design parameters, such as tendon configuration, pre-tensioning levels, and anchorage systems, influence the flexural capacity and serviceability of the beams. This research also discusses the challenges associated with practical implementation, including long-term durability, fatigue behaviour, anchoring, and cost implications. Through a critical analysis of experimental studies, analytical models, and numerical simulations, this study identifies gaps in existing knowledge and proposes future research directions to improve the understanding and application of composite tendons in prestressed concrete design. The insights presented herein are intended to guide structural engineers and researchers in developing more efficient and sustainable prestressed concrete systems.