Experimental testing of novel hybrid rubberised concrete double skin tubular columns with filament wound CFRP tube under axial compressive loading

Rubberised concrete formed by using recycled scrap tyre chips as the substitution for natural aggregates, has recently emerged as an important research topic. Though it conserves the mineral aggregates, it is associated with reduced compressive strength. Different confinement techniques with fiber-reinforced polymer (FRP) wrapping and steel have been commonly used to restore the lost strength that also provided some other benefits such as enhanced ductility and energy dissipation capacity. In this paper, a novel hybrid double-skin tubular column termed as “Hybrid RuDSTC” consisting of rubberised concrete, filament wound circular CFRP tube, and cold-formed circular steel tube was developed and experimentally explored to evaluate its performance under axial load. The parameters of the experimental investigation were void ratio, slenderness ratio, and percentage rubber replacement. Results showed that the novel Hybrid RuDSTCs can provide a promising sustainable solution with greater strain capacity compared to their unconfined counterparts. Better strain and enhanced ductility of the hybrid RuDSTCs compared to non-rubberised hybrid DSTCs enable their use in seismic prone regions and mining infrastructure