Each year, around one billion vehicle tyres are discarded globally, with less than 50% of them being recycled and the rest are dumped into landfills. Attempts have been made to substitute natural aggregates in concrete with rubber crumb from waste tyres to produce an environmentally friendly material known as rubberized concrete (RuC).
RuC has superior ductility and energy absorption capacity but lower stiffness, compressive strength, and tensile strength than normal concrete. The use of RuC as infill concrete in concrete-filled steel tubular (CFST) members can be regarded as a highly practical structural use, as the confinement given by the steel tube allows to overcome the shortcomings of RuC.
This study explores the behavior of RuCFST members subjected to flexural loading through experimental and non-linear finite element analysis. The effect of several parameters such as the percentage of rubber replacement in concrete, the effects of tube cross-sectional shape, type of infill materials, steel tube wall thickness, tensile strength of steel tube, slenderness and single/double skin steel tubes are examined in this project.