Hybrid double-skin tubular members for sustainable mining infrastructure

Hybrid FRP-concrete-steel double-skin tubular members (hybrid DSTMs) are a new form of hybrid structural members. A hybrid DSTM consists of an outer tube made of fibre reinforced polymer (FRP) and an inner tube made of steel, with the space between filled with concrete. The two tubes may be concentrically placed to produce a section form more suitable for compression members, or eccentrically placed to produce a section form more suitable for flexural members. In hybrid DSTMs, the three constituent materials are optimally combined to achieve several advantages not available with existing structural members, including their excellent corrosion resistance and energy-dissipation capacity. Hybrid DSTMs are therefore a sustainable alternative to existing structural components, especially for use in structures which are likely to be exposed to a harsh environment. This paper explains the rationale and advantages of this new form of structural members, presents an overview of existing and ongoing research on their structural behaviour and design, and discusses their potential applications in mining infrastructure.