What material is typically used in the process of pretensioning?

In the pretensioning process, steel is the primary material used due to its high strength and ability to withstand significant tensile stresses. The process involves stretching high-strength steel strands or cables before concrete is poured. Once the concrete hardens, tension is released from the steel, which compresses the concrete and enhances its performance under load. This method significantly improves the load-bearing capacity of precast concrete elements, making it suitable for bridges, beams, and other structural applications.

While concrete is essential in the overall structure, it is the steel that is actively pre-tensioned to create internal compressive forces, providing the desired structural benefits. Wood and plastic do not possess the required tensile strength or durability for this application, making steel the optimal choice in pretensioning techniques.