Enhancing Composite Steel-Concrete Beams: A Review of Strengthening Techniques, Performance, and Practical Applications

This paper reviews structural behavior, load resistance, and various strengthening techniques for composite steel-concrete beams. Composite beams, which combine steel and concrete to exploit the strengths of both materials, are integral to modern construction due to their efficiency and load-bearing capabilities. However, the need for strengthening these beams arises from factors such as increased service loads, material deterioration, and changes in design codes. This review discusses the primary methods of strengthening—steel plate strengthening, fiber-reinforced polymer (FRP) applications, and external post-tensioning—detailing their effectiveness, durability, and practical implementation challenges. Each method offers specific benefits and limitations, affecting their suitability based on structural demands and economic considerations. The paper concludes with a discussion on the combined use of these techniques to enhance both the flexural and interface capacities of composite beams, emphasizing the balance between serviceability and ultimate strength improvements. The comparative analysis aims to guide the selection of the most appropriate strengthening strategy, considering the evolving landscape of construction materials and methods aimed at prolonging the lifespan and functionality of composite steel-concrete structures.